S tates and localities can have significant interest in the manner and extent to which federal officials enforce provisions of the Immigration and Nationality Act (INA) regarding the exclusion and removal of unauthorized aliens. Some states and localities, concerned that federal enforcement disrupts families and communities, or infringes upon human rights, have adopted "sanctuary" policies limiting their cooperation in federal efforts. Other states and localities, in contrast, concerned about the costs of providing benefits or services to unauthorized aliens, or such aliens settling in their communities, have adopted measures to deter unauthorized aliens from entering or remaining within their jurisdiction. In some cases, such states or localities have also sued to compel federal officials to enforce the immigration laws, or to compensate them for costs associated with unauthorized migration. This report provides an overview of challenges by states to federal officials' alleged failure to enforce the INA or other provisions of immigration law. It begins by discussing (1) the lawsuits filed by six states in the mid-1990s; (2) Arizona's counterclaims to the federal government's suit to enjoin enforcement of S.B. 1070; and (3) Mississippi's challenge to the Deferred Action for Childhood Arrivals (DACA) initiative. It then describes the challenge brought by over 25 states or state officials in December 2014 to the Obama Administration's proposal to expand DACA and create a similar program for unauthorized aliens whose children are U.S. citizens or lawful permanent resident aliens (LPRs) (commonly known as DAPA). The report does not address challenges to the federal government's alleged failure to enforce the immigration laws that have been made by other parties, including private individuals, municipal officials, or, in one case, the people of a state (although not the state itself). But see CRS Legal Sidebar WSLG1145, "Sheriff Joe" Found to Lack Standing to Challenge the Obama Administration's Immigration Enforcement Priorities and Deferred Action Initiatives , by [author name scrubbed]. In the mid-1990s, six states which were then home to over half the unauthorized aliens in the United States —Arizona, California, Florida, New Jersey, New York, and Texas—each challenged the federal government's "fail[ure] to control illegal immigration." Each case raised somewhat different issues. However, all resulted in losses for the states both before the reviewing federal district court and on appeal. Limitations on standing—or who is a proper party to seek judicial relief from a federal court—were noted in some cases. However, even when standing was assumed, the states' constitutional and statutory claims failed, as discussed below. The following sections discuss how the courts viewed the most notable arguments made in the 1990s litigation, including those based on the Naturalization, Guarantee, and Invasion Clauses of the U.S. Constitution; the Tenth Amendment; and provisions of the INA. Several states claimed that the federal government's alleged failure to enforce the immigration laws imposed disproportionate costs upon them, which the federal government was obligated to reimburse pursuant to the Naturalization Clause. This clause—which has been recognized as one source of the federal government's authority to regulate immigration —expressly grants Congress the "Power ... [t]o establish a uniform Rule of Naturalization." The states' reasoning appears to have been that, insofar as the rule of naturalization is to be "uniform," the effects of immigration upon the states must also be uniform and, if they are not, the federal government has an affirmative duty to compensate those states that can be seen as disproportionately affected by immigration. However, ignoring the question of whether Congress's power over immigration is, in fact, co-extensive with its power over naturalization, the U.S. Courts of Appeals for the Second, Third, and Ninth Circuits found that the Naturalization Clause imposes no obligation upon the federal government to reimburse the states for any costs arising from an alleged "invasion" by unauthorized aliens, or to protect the states from harm by "non-governmental third parties." To the contrary, as the Second Circuit noted, the Supreme Court has upheld the federal government's exercise of its "plenary powers"—which include immigration —"even though the effects of such exercises of power may be onerous to the states." The courts similarly rejected the states' claims that the federal government violated the Guarantee Clause by failing to compensate them for their "immigration-related expenditures." The Guarantee Clause provides that the "United States shall guarantee to every State in this Union a Republican Form of Government," and the states' argument was essentially that the federal government deprived them of a republican form of government by "forcing" them to spend money on unauthorized aliens that they would not have had to spend if these aliens had been excluded or removed from the United States. This argument was, however, uniformly rejected by the Second, Third, Fifth, Ninth, and Eleventh Circuits. In some cases, the courts did so by noting that the Supreme Court has generally viewed alleged violations of the Guarantee Clause as involving nonjusticiable "political questions," or questions which are committed to the executive and/or legislative branches, and which lack judicially discoverable and manageable standards for resolving. In other cases, the courts noted that nothing in the state's complaint suggested that the state had been deprived of a republican form of government because the state's "form [and] method of functioning" remained unchanged, and the state's electorate had not been "deprived of the opportunity to hold state and federal officials accountable at the polls for their respective policy choices." Claims that the federal government's alleged failure to enforce the immigration laws violated the Invasion Clause—which requires the federal government to protect the states "against Invasion" —were similarly rejected by the Second, Third, Ninth, and Eleventh Circuits. Most commonly, this was because the courts viewed the legislative and executive branches as having been tasked with determining how the immigration laws are to be enforced, while the judicial branch was seen to lack manageable standards for determining whether or when the entry of unauthorized aliens constituted an "invasion." Several courts also found, in the alternative, that the Invasion Clause was inapplicable because the states were not threatened by incursions of foreign or domestic states. The states' claims that the federal government violated the Tenth Amendment by "forcing" them to provide public benefits and services to unauthorized aliens were also uniformly rejected by the Second, Third, Fifth, Ninth, and Eleventh Circuits. Here, the courts relied upon somewhat different reasoning as to each of the three main types of benefits and services which the states alleged that the federal government had "commandeered." First, as to Medicaid spending, the courts found that the states had agreed to provide certain emergency medical services to unauthorized aliens as a condition of states' receipt of federal funds. Such conditions, in the courts' view, represented a permissible exercise of Congress's spending power, rather than impermissible commandeering. Second, as to the costs of incarcerating unauthorized aliens, the courts noted that these aliens were jailed pursuant to state law, rather than any dictates of the federal government and, thus, they found no commandeering. Third, and finally, as to elementary and secondary education, the courts noted that the states were obligated to provide such education to unauthorized alien children as a result of the Constitution, as construed by the Supreme Court in Plyler v. Doe , and not as the result of a command of the federal government. Thus, in the courts' view, this, too, did not represent commandeering. The states' statutory claims—alleging that federal officials violated specific provisions of the INA or other statutes by failing to exclude or remove unauthorized aliens, or compensate the states for the costs associated with such aliens—were no more successful than their constitutional arguments. The states cited a number of provisions in support of these claims, including Section 103(a)(5) of the INA, which at that time tasked the Attorney General with the "duty to control and guard the boundaries and borders of the United States against the illegal entry of aliens" ; the former Section 1252(a)(2)(A) of Title 8 of the U.S. Code , which called for the Attorney General to take any alien convicted of an aggravated felony into custody upon the alien's release from state custody or supervision; the former Section 1252(c) of Title 8 of the U.S. Code , which established a six-month period following the issuance of a final order of removal for federal officials to effectuate the alien's departure from the United States; the former Section 1252( l ) of Title 8 of the U.S. Code , which directed the Attorney General to begin deportation proceedings for aliens convicted of deportable offenses "as expeditiously as possible after the date of conviction"; Section 276 of the INA, which establishes criminal penalties for "illegal reentry" (i.e., unlawfully re-entering the United States after having been removed); and Section 1365 of Title 8 of the U.S. Code , which provides for the reimbursement of costs incurred by the states for the imprisonment of unauthorized aliens or Cuban nationals who have been convicted of felonies. However, all the states' claims were seen to involve matters that were committed to agency discretion as a matter of law and, thus, not reviewable by the courts. Notably, all the statutes cited by the states in making these claims included the word "shall." In no case, though, did an appellate court specifically address the statute's use of this word, or whether "shall" could be construed to indicate mandatory agency action, in its published decision. This was so even when the provision of immigration law in question did not, in itself, include language which clearly evidenced that federal officials had some discretion in enforcing the law. It should also be noted that, in three of the six cases, the appellate court expressly rejected the suggestion that federal officials' alleged failure to enforce the immigration laws could be seen as an "abdication" of their statutory responsibilities. The Supreme Court's 1985 decision in Heckler v. Chaney expressly recognized an exception to the presumption that agency decisions not to undertake enforcement actions are "committed to agency discretion by law" and, thus, immune from judicial review under the Administrative Procedure Act (APA). This exception would permit review when "the agency has 'consciously and expressly adopted a general policy' [of nonenforcement] that is so extreme as to amount to an abdication of its statutory responsibilities." However, the federal courts of appeals found that the federal government's immigration enforcement policies in the mid-1990s did not constitute such an abdication, apparently because the states could not allege that the federal government was "doing nothing" to enforce the immigration laws. Instead, in the courts' view, the states questioned the effectiveness of federal policies and practices, and "[r]eal or perceived inadequate enforcement of immigration law does not constitute a reviewable abdication of duty." In 2011, over a decade after the mid-1990s litigation, Arizona asserted counterclaims challenging the federal government's alleged failure to enforce the immigration laws in the litigation over Arizona's Support Our Law Enforcement and Safe Neighborhoods Act (commonly known as "S.B. 1070"). Arizona had adopted S.B. 1070 in 2010 in an attempt to deter unauthorized aliens from settling in the state by requiring that state and local police check the immigration status of all persons whom they stop, arrest, or detain. S.B. 1070 also made it a state crime to engage in certain conduct thought to facilitate the presence of unauthorized aliens within the state. The federal government sought to enjoin enforcement of S.B. 1070 on the grounds that it was preempted by federal law. Arizona responded, in part, by alleging that federal policies and practices as to immigration enforcement ran afoul of various provisions of the Constitution and federal statute. In particular, Arizona alleged that federal officials had violated the Invasion and Domestic Violence Clauses, as well as the Tenth Amendment, by, respectively, failing to protect Arizona from "invasion" by aliens unlawfully entering the United States and "refusing" to reimburse the state for the "costs and damages associated with illegal immigration in Arizona." Arizona also alleged that federal officials had failed to comply with statutory mandates to achieve and maintain "operational control" of the Arizona-Mexico border, pursue and effectuate the removal of unauthorized aliens who are found within the interior of the United States, and reimburse states for the costs of detaining "criminal aliens" pursuant to the State Criminal Alien Assistance Program (SCAAP). The federal government challenged Arizona's standing to raise all of these claims other than that as to reimbursement pursuant to SCAAP. However, the reviewing federal district court "presum[ed]" that Arizona had standing because (1) the federal government did not question whether "illegal immigration" constituted an injury in fact; (2) Arizona had alleged facts indicating that unauthorized aliens' conduct and choices in crossing into Arizona were directly influenced by federal policies and practices; and (3) ordering the federal government to "deploy ... temporary measures" to secure the border would provide Arizona "some relief." Arizona did not fare as well on the merits of its arguments. The reviewing federal district court first found that Arizona's claims as to the Invasion Clause and the Tenth Amendment were precluded by the litigation in the mid-1990s, or, alternatively, settled in the federal government's favor by Ninth Circuit precedent. The court similarly found that Arizona's remaining constitutional claim—alleging a violation of the Domestic Violence Clause that had not been raised in the mid-1990s litigation—was also settled by Ninth Circuit precedent finding that the clause applies only to "insurrections, riots, and other forms of civil disorder," and not "ordinary crimes." The court also viewed the Domestic Violence Clause as implicating nonjusticiable political questions. The reviewing federal district court then found that Arizona's various statutory claims involved actions that were committed to agency discretion by law and, thus, were not subject to review by the courts. In so finding, the court specifically looked at provisions of immigration law that direct the Secretary of Homeland Security to "take all actions the Secretary determines necessary and appropriate to achieve and maintain operational control" over the U.S. border within 18 months after the enactment of the Secure Fence Act of 2006; prioritize the incarceration of unauthorized "criminal aliens" and reimburse states through SCAAP for the costs of incarcerating such aliens; establish procedures for removing unauthorized aliens apprehended in the interior of the United States; and bar federal, state, and local officials from restricting the sharing of information regarding persons' citizenship or immigration status. However, the court concluded that each provision involved actions that are committed to agency discretion by law. In some cases, the court reached this conclusion because the statute provided no standard by which the court could judge the propriety of federal officials' actions, as with the construction of the border fence, where "no deadline mandates completion of the fencing and infrastructure developments or any required discrete action by a specified time." In other cases, the court noted that the statutes themselves grant federal officials "substantial discretion," as was the case with "determining where to build fencing, where to use alternative infrastructure improvements rather than fencing, and how best to develop a comprehensive program to prevent illegal immigration." In no case did the court, in its published opinion, note the use of "shall" in any of these statutes, or discuss whether this word could be construed to indicate mandatory action. The court further found the specific actions challenged by Arizona—which included prioritizing certain enforcement efforts and "considering changes in the interpretation and enforcement of immigration laws that would 'result in meaningful immigration reform absent legislative action'"—did not constitute an abdication of the Executive's statutory responsibilities. The court did so, in part, because Arizona conceded that federal officials "continue to enforce federal immigration laws in accordance with priorities established by the federal government." Thus, according to the court, while Arizona "disagrees" with federal enforcement priorities, its "allegations do not give rise to a claim that [federal officials] have abdicated their statutory responsibilities." One year later, in 2012, Mississippi raised similar claims about federal officials' alleged failure to enforce the immigration laws when it joined a challenge brought by some U.S. Immigration and Customs Enforcement (ICE) agents to the Obama Administration's Deferred Action for Childhood Arrivals (DACA) initiative. This challenge arose from the Administration's decision to grant some "unauthorized aliens" who had been brought to the United States as children and raised here deferred action—one type of relief from removal—and, in many cases, work authorization. The ICE agents and Mississippi asserted that this initiative violates the Take Care Clause, impinges upon Congress's legislative powers, and contradicts certain provisions in Section 235 of the INA, which some assert require that unauthorized aliens be placed in removal proceedings. They also alleged that it runs afoul of the Administrative Procedure Act (APA) because the Obama Administration did not promulgate regulations before making deferred action—which the plaintiffs viewed as a "benefit," not an exercise of prosecutorial discretion—available to unauthorized aliens who had been brought to the United States as children. The ICE agents were found to have standing to raise these challenges and, at least initially, prevailed before the reviewing federal district court on their claim that DACA runs afoul of three purportedly "interlocking" provisions in Section 235 of the INA which state that 1. any alien present in the United States who has not been admitted shall be deemed an applicant for admission; 2. applicants for admission shall be inspected by immigration officers; and 3. in the case of an alien who is an applicant for admission, if the examining immigration officer determines that an alien seeking admission is not clearly and beyond a doubt entitled to be admitted, the alien shall be detained for removal proceedings. In particular, the court noted that each of the three provisions includes the word "shall," and took the view that "shall" indicates mandatory agency action. However, this same court later found that it lacked jurisdiction over the ICE agents' claims. This finding was affirmed on appeal by the Fifth Circuit in a decision which suggests—but does not directly hold—that the Fifth Circuit may not view Section 235 of the INA as barring the Executive from granting deferred action to unauthorized aliens. Mississippi, in contrast, was found not to have standing because the reviewing court viewed its alleged injury as "conjectural and based on speculation" and, thus, insufficiently concrete to satisfy the constitutional requirements of standing. This injury consisted of the fiscal costs associated with unauthorized aliens residing in the state who were allegedly enabled to remain there as a result of DACA and Obama Administration guidance regarding the exercise of prosecutorial discretion in civil immigration enforcement. The federal government did not contest that the expenditure of state funds could qualify as an invasion of a legally protected interest sufficient to establish standing under the "proper circumstances." Rather, the federal government argued that such circumstances were not present in the instant case because Mississippi relied upon a 2006 report—which pre-dated DACA—to show the costs it incurred as the result of the Obama Administration's actions. The district court agreed, and also noted that Mississippi had offered only "conclusory allegations" that the unauthorized aliens granted deferred action would have been removed but for the DACA initiative, or that DACA had resulted in a decrease in the total number of aliens removed by the federal government. The district court's decision as to Mississippi's standing was affirmed by the Fifth Circuit on appeal. In so doing, the Fifth Circuit noted that it viewed Mississippi's alleged injury as "purely speculative" because it "is not supported by any facts" showing that Mississippi's costs increased, or will increase, as a result of DACA. One judge did, however, issue a concurring opinion which emphasized that concrete evidence that an injury has occurred or will occur is not necessary for standing for certain types of claims, but did not view Mississippi as making such claims. Most recently, in December 2014, over 25 states or state officials filed suit challenging the Obama Administration's announcement that it is expanding the DACA program to cover additional aliens who had been brought to the United States as children, and creating a DACA-like program for unauthorized aliens who are the parents of U.S. citizens or LPRs (commonly known as DAPA). In particular, the states assert that these new programs violate the Take Care Clause and separation of powers principles of the Constitution, federal immigration law, and substantive and procedural requirements of the APA. The federal government disputes these assertions. It also maintains that the plaintiffs lack standing, and that the challenged programs represent an exercise of enforcement discretion and, as such, are immune from judicial review. In a decision issued on February 16, 2015, the U.S. District Court for the Southern District of Texas found that the states have standing to challenge DAPA and the DACA expansion, and that the challenged programs are judicially reviewable. It also imposed a preliminary nationwide ban on the implementation of these programs after finding that the states are likely to prevail on the merits of their argument that the memorandum establishing the programs constitutes a substantive rule, but was issued without compliance with the notice-and-comment procedures required for such rules under the APA. The federal government filed an emergency expedited motion to stay the injunction with the district court, which was denied because the district court viewed its "original findings and rulings" as "correct." The federal government also appealed the district court's decision regarding standing, reviewability, and the procedural requirements of the APA to the Fifth Circuit. The government requested that the Fifth Circuit stay the injunction pending resolution of this appeal. On May 26, 2015, the Fifth Circuit issued a decision rejecting, by a vote of 2 to 1, the federal government's request for the stay because it viewed the federal government as failing to make the requisite showing that it was likely to succeed on the merits of its arguments that (1) the states lack standing; (2) DAPA and the DACA expansion are not subject to judicial review; and (3) the memorandum establishing the challenged programs constitutes an interpretative rule, not a substantive one. Subsequently, on November 9, 2015, the Fifth Circuit denied, again by a vote of 2 to 1, the government's appeal, in part, because it agreed with the district court's reasoning in finding that the states have standing to challenge DAPA and the DACA expansion, the programs are judicially reviewable, and their establishment represents a substantive rule that should have been subject to notice-and-comment rulemaking. However, the Fifth Circuit also went beyond the district court's analysis in finding that DAPA and the DACA expansion are impermissible because they conflict with provisions of the INA or, alternatively, represent unreasonable interpretations of the INA. The Supreme Court granted the federal government's petition for review of the Fifth Circuit's decision. However, an evenly divided Supreme Court ultimately issued a decision that, consistent with recent practice, affirmed the Fifth Circuit's decision without any opinion or indication of the Justices' voting alignment. This means that the preliminary nationwide ban on the implementation of DAPA and the DACA expansion that the district court imposed in February 2015, when it granted the states' motion for a preliminary injunction, remains in place, at least for now. The district court continues to hear arguments on whether to permanently enjoin implementation of these programs. In affirming the district court on the questions of standing, reviewability, and the need for rulemaking, the majority of the Fifth Circuit did not significantly add to or alter the district court's analysis. In particular, as to standing, the majority noted that Texas satisfied the requirements for constitutional, Article III standing, as well as those for prudential standing—an additional hurdle for claims brought under the APA. Relying on Massachusetts v. EPA , the majority first noted that the plaintiff-states are entitled to "special solicitude" in the court's standing inquiry. As for constitutional standing, the majority concluded that if DAPA, in particular, were implemented, Texas would suffer a concrete injury because the state would incur "significant costs" by having to issue state-subsidized driver's licenses to DAPA beneficiaries. With regard to prudential standing, the majority concluded that Texas's interest in denying public benefits to "illegal aliens"—something which Congress generally requires, absent the enactment of a state law that expressly provides for their eligibility —falls within the "zone of interests" regulated by the INA. The dissent, however, characterized the majority's standing analysis as "deeply troublesome," noting, in particular, separation of powers concerns because, in the dissenting judge's view, the majority ruling would "inject courts into far more federal-state disputes and review of the political branches." Concerning the court's authority to review DAPA and the DACA expansion, the majority recognized that there are limitations to judicial review of specific decisions of the Secretary of Homeland Security, but concluded that none of those limitations pertains to the decision to grant "lawful presence" to millions of aliens. The majority also concluded that it can review DAPA and the DACA expansion to determine whether the Executive exceeded its statutory powers because these programs affirmatively confer lawful presence on aliens who entered or remained in the United States in violation of the immigration laws, as well as permit them to receive authorization to work in the United States. These programs are thus not tantamount to agency decisions not to take enforcement action, in the majority's view. The dissent, though, disagreed that this was a basis for review, reasoning that the ability of deferred action beneficiaries to apply for work authorization is not a function of DAPA but of decades-old regulations whose permissibility was not challenged by the plaintiff-states. The majority also affirmed the district court's ruling that DAPA and the DACA expansion should have been implemented through notice-and-comment rulemaking pursuant to the APA. The majority did so, in part, because it viewed the programs as legally binding, not as a policy statement. It found no error in the lower court's factual finding that, although the memorandum announcing DAPA and the DACA expansion "facially purports to confer discretion," that discretion is "merely pretext," given the low rate of rejection in the 2012 DACA program and the provisions made for handling DAPA applications (a conclusion which the dissenting judge would have found clearly erroneous). The majority similarly found that DAPA is not a procedural rule, since it establishes substantive standards by which applications for deferred action are evaluated. The majority went beyond the district court's ruling, however, in finding that DAPA and the DACA expansion violate the APA substantively, as well as procedurally, because they are "not in accordance with the law" and "in excess of statutory ... authority." In so doing, the majority noted Fifth Circuit precedent that it "may affirm a district court's judgment on any grounds supported by the record." It further noted that it assumed that the permissibility of DAPA and the DACA expansion should be addressed under the precedent of Chevron USA, Inc. v. Natural Resources Defense Council , which calls for courts to defer to agency interpretations of their governing statutes where Congress has not "directly spoken to the precise question at issue," and the agency's interpretation of an ambiguous statute is a reasonable one. The majority found, however, that Congress has spoken to the precise questions at issue here in such a way as to preclude DAPA and the DACA expansion. In particular, it pointed to the INA's provisions regarding (1) which aliens may lawfully enter and remain in the United States, (2) discretionary relief from removal, and (3) work authorization. For example, it noted that DAPA would treat aliens who entered or remained in the United States in violation of federal immigration law and are the parents of U.S. citizens or LPRs as "lawfully present," while the INA permits "illegal aliens to derive a lawful immigration classification from their children's immigration status" only if the child is a U.S. citizen (not an LPR) who is at least 21 years of age, and the alien leaves the United States and waits at least 10 years before applying for one of a limited number of family-preference visas. Alternatively, the majority found that even if Congress is not seen to have spoken on the precise questions at issue, the Executive's interpretation is "unreasonable" because it is "manifestly contrary" to the INA provisions previously noted. The majority further noted the "major policy" exception to Chevron deference—which is based on the view that Congress does not intend to delegate policy decisions "of economic and political magnitude to an administrative agency" when enacting an ambiguous statute—in finding DAPA and the DACA expansion impermissible. It also rejected the view that DAPA and the DACA expansion are grounded in historical practices to which Congress can be seen to have acquiesced by not taking action to bar the practices. The dissenting judge, in contrast, would not have reached the question of whether DAPA and the DACA expansion substantially violate the APA, given that the district court had "expressly declined" to do so, and the Fifth Circuit had received what the dissenting judge viewed as "limited briefing" on the issue. The Supreme Court's 4-4 split in United States v. Texas leaves in place a Fifth Circuit decision that upheld a preliminary nationwide ban on the implementation of DAPA and the DACA expansion, and that could complicate certain executive actions as to immigration in the future (e.g., relatively large-scale grants of deferred action, parole in place, extended voluntary departure, or other relief from removal that would result in aliens being deemed "lawfully present" and obtaining work authorization). In other contexts, though, states' ability to challenge alleged federal "failures" to enforce the immigration laws in the future may be more limited than it might first appear. The 2015 litigation in Texas does mark the first time that a state has obtained a court order directing the federal government to take certain actions (i.e., delaying implementation of DAPA and the DACA expansion) in response to state allegations that the federal government is failing to enforce the INA. On the other hand, the facts and circumstances involved in the 2015 Texas litigation are arguably distinguishable from those in earlier cases and, thus, potentially limit this decision's relevance to any future state challenges to federal enforcement of the immigration laws. First, there are the specific facts and circumstances which prompted the reviewing courts to find that Texas, in particular, has Article III standing to challenge DAPA and the DACA expansion. This finding was based, in part, on Texas's documentation of the costs it would incur in issuing driver's licenses to DAPA beneficiaries. Moreover, because the federal government had advocated a position in prior litigation over the issuance of driver's licenses to DACA beneficiaries that Texas asserted would result in the federal government requiring it to issue driver's licenses to DAPA beneficiaries , Texas could counter the argument that these costs arose due to state law or the Constitution, and not the federal government's actions. Both factors were arguably significant, particularly to the district court. Mississippi's alleged injury in the Crane litigation, for example, was seen as inadequate for standing because Mississippi did not show that the implementation of DACA had increased, or would increase, its costs. Certain claims in the mid-1990s litigation similarly failed because the states were seen as incurring specific costs associated with unauthorized aliens because of grant conditions (to which the state had agreed), state laws, or constitutional requirements, and not the dictates of the federal government. Second, and relatedly, there is the specific form that the federal government's alleged failure to enforce the immigration laws took in the 2015 Texas decision. Namely, the Obama Administration proposed to grant deferred action (one type of relief from removal) to certain unauthorized aliens, a proposal which could result in those aliens becoming eligible for certain "benefits" under existing law (e.g., work authorization, Social Security numbers). In finding that this particular form of nonenforcement of the immigration laws is subject to judicial review, both the district court and the majority of the Fifth Circuit emphasized that they view the granting of deferred action as involving an "affirmative action" on the Executive's part, and not simply a matter of an agency's enforcement priorities, or nonenforcement of the laws as to individual aliens and groups of aliens. Both of these (i.e., enforcement priorities, nonenforcement as to individuals) would appear to be within the Executive's discretion, in the courts' view, and thus not subject to judicial review. Indeed, the district court even suggested, in denying the federal government's emergency expedited motion to stay the injunction, that immigration officials could achieve their purpose of designating potential DAPA beneficiaries as "low priorities" for removal by giving them written documentation to this effect, so long as this documentation does not involve a grant of deferred action.

Summary: States and localities can have significant interest in the manner and extent to which federal officials enforce provisions of the Immigration and Nationality Act (INA) regarding the exclusion and removal of unauthorized aliens. Depending upon the jurisdiction's specific concerns, this interest can be expressed in various ways, from the adoption of "sanctuary" policies limiting the jurisdiction's cooperation in federal enforcement efforts to the enactment of measures to deter unauthorized aliens from entering or remaining within the jurisdiction. In some cases, states or localities have also sued to compel federal officials to enforce the INA and other relevant laws. In the mid-1990s, six states which were then home to over half the unauthorized aliens in the United States—Arizona, California, Florida, New Jersey, New York, and Texas—each filed suit alleging that federal officials' failure to check unauthorized migration violated the Guarantee and Invasion Clauses of the Constitution, the Tenth Amendment, and provisions of the INA. Concerns regarding standing—or who is a proper party to seek relief from a federal court—were sometimes noted. However, even when standing was assumed, the constitutional claims were seen to involve nonjusticiable "political questions," or failed on their merits. The states' statutory claims were similarly seen to involve matters committed to agency discretion by law and, thus, not reviewable by the courts. In three cases, the courts also noted that federal officials' alleged failure to control unauthorized migration did not constitute a reviewable "abdication" of their statutory duties. Over a decade later, in 2011, Arizona asserted counterclaims challenging the federal government's alleged failure to stop unauthorized migration in the litigation over Arizona's S.B. 1070 measure. Although the court presumed that Arizona had standing, it rejected Arizona's claims regarding violations of the Invasion and Domestic Violence Clauses, Tenth Amendment, and immigration laws. Some claims were seen as precluded or otherwise settled by the earlier litigation. Others were found to involve nonjusticiable political questions, or otherwise failed. The court also rejected the argument that federal officials had abdicated their statutory duties. Subsequently, in 2012, Mississippi, along with some U.S. Immigration and Customs Enforcement agents, challenged the Obama Administration's Deferred Action for Childhood Arrivals (DACA) initiative on the grounds that it runs afoul of the Take Care Clause, separation of powers, INA, and Administrative Procedure Act (APA). The ICE agents initially prevailed in their claim that DACA is contrary to the INA, although their case was ultimately dismissed on other grounds. However, Mississippi was found to lack standing because it could not show that aliens granted deferred action would have been removed had the Executive not implemented DACA. Most recently, in December 2014, over 25 states or state officials filed suit challenging the Administration's expansion of DACA and the creation of a DACA-like program for aliens who are parents of U.S. citizens or lawful permanent residents (known as DAPA). The states allege that these programs run afoul of the Take Care Clause and separation of powers principles of the Constitution, the INA, and substantive and procedural requirements of the APA. After finding that the states have standing, and that DAPA and the DACA expansion are judicially reviewable, a federal district court imposed a preliminary nationwide ban on the implementation of these programs in February 2015, on the grounds that the states are likely to prevail in their argument that the programs run afoul of the APA's procedural requirements. Subsequently, in November 2015, the U.S. Court of Appeals for the Fifth Circuit affirmed the lower court's finding as to the procedural violation of the APA, and also found for the states on their claim that DAPA and the DACA expansion substantively violate the APA because these programs are "not in accordance with law" and "in excess of statutory ... authority." The Supreme Court granted review, but the Justices ultimately split evenly, four votes to four votes. Consistent with recent practice in cases with such splits, the Court affirmed the Fifth Circuit's decision without issuing an opinion.