In 1993, after many months of study, debate, and political controversy, Congress passed and President Clinton signed legislation establishing a revised "[p]olicy concerning homosexuality in the armed forces." The new legislation reflected a compromise regarding the U.S. military's policy toward members of the Armed Forces who engage in homosexual conduct. This compromise, colloquially referred to as "Don't Ask, Don't Tell (DADT)," held that "[t]he presence in the armed forces of persons who demonstrate a propensity or intent to engage in homosexual acts would create an unacceptable risk to the high standards of morale, good order and discipline, and unit cohesion which are the essence of military capability." Service members are not to be asked about, nor allowed to discuss, their sexual orientation. This compromise notwithstanding, the issue has remained both politically and legally contentious, and Congress ultimately passed legislation to repeal DADT. As described in greater detail below, this repeal became effective on September 20, 2011. This report provides a legal analysis of the various constitutional challenges that have been brought against DADT. For policy analyses, see CRS Report R42003, The Repeal of "Don't Ask, Don't Tell": Issues for Congress , by [author name scrubbed], and CRS Report R40782, "Don't Ask, Don't Tell": Military Policy and the Law on Same-Sex Behavior , by [author name scrubbed]. Under DADT, which was repealed on September 20, 2011, a member of the Armed Forces could be discharged from the military if (1) the member engaged in, attempted to engage in, or solicited another to engage in a homosexual act or acts; (2) the member stated that he or she was a "homosexual or bisexual"; or (3) the member married or attempted to marry someone of the same sex. The statute defined "homosexual" as an individual who "engages in, attempts to engage in, has a propensity to engage in, or intends to engage in homosexual acts," and similarly defined "bisexual" as an individual who "engages in, attempts to engage in, has a propensity to engage in, or intends to engage in homosexual and heterosexual acts." The term "homosexual" was also defined to include the terms "gay" and "lesbian." It is important to note that DADT did not prohibit the military from questioning new recruits or members about their sexual orientation, although the legislation establishing the policy did contain a statement reflecting the sense of Congress that such questioning should be suspended but could be reinstated if the Secretary of Defense determined such inquiries were necessary to implement the policy. Indicating that such questioning may have been discouraged, the Department of Defense (DOD) Directive implementing the DADT policy stated that sexual orientation is a "personal and private matter and is not a bar to current military service ... unless manifested by homosexual conduct." The DADT regulations, therefore, were based on conduct, including verbal or written statements. Since sexual "orientation" is "personal and private," DOD was not to ask and personnel were not to tell. If an individual chose to make his or her homosexual "orientation" public, however, an investigation and discharge were likely to occur. It is also important to note that the law contained no mention of "sexual orientation," although DOD defined the term as "[a]n abstract sexual preference for persons of a particular sex, as distinct from a propensity or intent to engage in sexual acts." Therefore, both the law and the regulations distinguished between sexual orientation and sexual conduct, and both were structured entirely around the concept of homosexual conduct as opposed to orientation, including statements concerning an individual's sexuality. As a result, attempts to implement the statute, or analyze and evaluate it, in terms of sexual orientation, often resulted in confusion and ambiguity. In recent years, several Members of Congress expressed interest in amending or repealing DADT, as did some military officials. In February 2010, Secretary of Defense Robert Gates established a DOD working group to review issues that could arise if DADT were repealed. Gates simultaneously directed DOD to review regulations regarding DADT and to propose any changes that would allow DOD to "enforce the law in a fairer and more appropriate manner." Based on this review, Secretary Gates announced revisions to the DADT regulations in March 2010 that eased certain requirements for discharging service members pursuant to DADT. Subsequently, DOD issued the results of its study and concluded that repeal of DADT would pose a low risk to military readiness. In a related move, Congress passed legislation to repeal DADT if certain conditions were met. Under the Don't Ask, Don't Tell Repeal Act of 2010, DADT repeal became effective 60 days after the President, the Secretary of Defense, and the Chairman of the Joint Chiefs of Staff certified that they considered the recommendations contained in a recent Department of Defense (DOD) report on the effect of repeal; that DOD has prepared the necessary policies and regulations to implement the new law; and that the implementation of such policies and regulations "is consistent with the standards of military readiness, military effectiveness, unit cohesion, and recruiting and retention of the Armed Forces." This certification occurred on July 22, 2011, and the repeal took effect on September 20, 2011. In general, DADT repeal appears to have proceeded smoothly. DOD has issued new policy guidance, as well as identified benefits that can be extended to the same-sex partners of service members. However, the availability of such benefits was originally limited by Section 3 of the federal Defense of Marriage Act (DOMA), which, for purposes of federal law, defined marriage as between one man and one woman. On June 26, 2013, the Supreme Court struck down this provision as unconstitutional. In the wake of this decision, DOD announced that military spouses in same-sex marriages will be eligible to receive military benefits that had previously been available only to opposite-sex spouses. Meanwhile, in the midst of the debate over repealing DADT, several court cases challenging the constitutionality of DADT continued to unfold. For historical purposes, these lawsuits are described in detail below, although such challenges became moot after repeal took effect. Constitutional challenges to military policies regarding homosexual conduct began to accelerate following implementation of the DADT compromise in 1993. Similar challenges have also been brought against Article 125 of the Uniform Code of Military Justice, which provides for court-martial and punishment as the court-martial may direct for acts of sodomy committed by military personnel. The Supreme Court never directly considered a challenge to DADT and refused to review the military's policy on several occasions. Although the Court has never directly addressed the constitutionality of DADT, the Court has considered cases involving allegations of discrimination by the military, as well as cases involving the rights of individuals who engage in homosexual conduct, and these cases are informative. Indeed, most federal courts that have rejected challenges to DADT have relied upon judicial precedents involving "special deference" to the political branches to affirm the "considered professional judgment" of military leaders to discipline or discharge a service member for homosexual conduct or speech. This doctrine of military deference and its application in several Court decisions involving allegations of discrimination by the military are discussed in greater detail below. Like the doctrine of military deference, Court rulings in two cases involving homosexual conduct— Bowers v. Hardwick and Lawrence v. Texas —have also played a prominent role in lower court cases involving constitutional challenges to DADT. In its 1986 ruling in Bowers , the Court held that there was no fundamental right to engage in consensual homosexual sodomy. Based on this decision, the courts uniformly ruled that the military could constitutionally discharge a service member for overt homosexual behavior. Complicating the legal picture, however, was the Court's 2003 ruling in Lawrence , which expressly overruled Bowers and declared unconstitutional a Texas law that prohibited sexual acts between same-sex couples. In Lawrence , the Court held that the "liberty" interest in privacy guaranteed by the due process clause of the Fourteenth Amendment protects a right for adults to engage in private, consensual homosexual conduct, expressly overruling Bowers 's contrary conclusion. In particular, the community's moral disapproval of homosexuality was no "rational" justification for deploying the power of the state to enforce those views. According to the Court: The petitioners are entitled to respect for their private lives. The State cannot demean their existence or control their destiny by making their private sexual conduct a crime. The right to liberty under the Due Process Clause gives them the full right to engage in their conduct without the intervention of the government. It is a promise of the Constitution that there is a realm of personal liberty which the government cannot enter. The Texas statute furthers no legitimate state interest which can justify its intrusion into the personal and private life of the individual. As noted above , earlier federal appellate courts, relying on Bowers , uniformly ruled that the military ban on homosexual acts intruded upon no constitutionally protected right and was "rationally related" to legitimate military needs for "unit cohesion" and discipline. Moreover, by equating the admission of homosexuality by individual service members—unless demonstrated otherwise—with "propensity" for illegal conduct, the DADT policy successfully avoided equal protection and First Amendment challenge as well. After Lawrence , however, the constitutional bulwark of Bowers began to crumble, arming opponents of Article 125 and DADT with an argument that such military policies abridge the due process right to privacy of service members who are gay. But to prevail in that argument, challengers had to demonstrate that findings by Congress regarding those policies defy minimal rationality, a weighty burden given the deference historically accorded the political branches in the management of military affairs. The precise standard of judicial review, however, has yet to be firmly established.