Article III of the Constitution established the judicial branch of the United States, consisting of the Supreme Court and of any "inferior Courts as the Congress may from time to time ordain and establish.... " To staff such courts, the Constitution empowered life-tenured and salary-protected judges to adjudicate certain "cases" or "controversies," including cases arising under the Constitution. The Supreme Court, in Marbury v. Madison, held that the judicial power to interpret the Constitution necessarily includes the power of judicial review —that is, the power to countermand the decisions by other government agents because a given decision contravenes the Constitution. Judicial review is not only a potent tool for the judiciary—it is also a controversial one, in that unelected federal judges possess the power to undo the decisions of the branches that are theoretically the most responsive to the people. From the early days of the republic to the New Deal to modern times, the history of the United States is replete with examples of conflicts between the political branches and the judiciary over the latter's use of the power of judicial review. Indeed, over the last two terms of the Supreme Court, the High Court, whether in striking down Section 3 of the federal Defense of Marriage Act (DOMA) in United States v. Windsor or Section 441 of the Federal Election Campaign Act (FECA) in McCutcheon v. FEC , has shown a willingness to exercise its power to invalidate a congressionally enacted law, and, in turn, the Supreme Court's exercise of the power of judicial review has led to sharp criticisms of the Court and accusations of judicial "activism" thwarting the will of the majority. Notwithstanding the recent high-profile matters in which the Court has exercised its often controversial power of judicial review, judicial invalidation of democratically enacted laws on constitutional grounds remains relatively rare at the Supreme Court. Of the 75 opinions issued by the Roberts Court in the October 2013 term, only one decision— McCutcheon— invalidated a congressionally enacted law on constitutional grounds, and three cases declared a positive enactment under state law to be unconstitutional. The Court's apparent reticence in using judicial review is supported by long-standing case law cautioning against judicial review and counseling courts to "avoid" unnecessarily broad rulings on constitutional questions. For example, the Supreme Court has established a "time-honored presumption" that a congressionally enacted law is constitutional, and, as a general rule, courts should not "pass on questions of constitutionality ... unless such adjudication is unavoidable." Indeed, the Supreme Court has established a host of loosely related rules generally called the constitutional avoidance doctrine that discourage a federal court from issuing broad rulings on matters of constitutional law. After providing general background on the power of judicial review and the major theories justifying the constitutional avoidance doctrine, this report explores the various rules that allow a court to avoid a broad ruling that invalidates a democratically enacted law and the logic behind those rules. The report concludes with an exploration of how the doctrine of constitutional avoidance has influenced some of the recent jurisprudence of the Roberts Court, criticisms of the doctrine, and the implications for Congress. In establishing the federal tripartite government, the Framers of the Constitution, while proponents of democracy, were wary of any form of unchecked power, even when that power was lodged in a democratic majority. As a consequence, the Framers envisioned a written Constitution, which protected specific values, principles, and rights, as a limit of what could be changed through ordinary political processes. Because the political branches may not be expected to always adhere to the constitutional limitations placed on each body, as these branches are most directly responsive to the often temporary whims of the people, the federal judiciary established under Article III was deliberately designed by the Framers of the Constitution to be a "countermajoritarian" branch that interpreted the written Constitution and protected its principles. The Constitution did this by "insulating the federal judiciary" from potential pressures, from either the political branches or the public, which could potentially "skew the decision making process or compromise the integrity or legitimacy of federal court decisions." The key sources of the judiciary "insulation" from the political processes are the Good Behavior Clause and the Compensation Clause of Article III. For the Framers, the Good Behavior Clause, by creating a "permanent tenure of judicial offices," ensures an "independent spirit in judges," and the Compensation Clause, by creating a "fixed provision for [the judiciary's] support," prevents the political branches from having power over a judge's subsistence and, with that, "power over his will." While the Constitution itself is silent on the power of judicial review, in Marbury v. Madison, Chief Justice John Marshall formally concluded that the logic of the written Constitution coupled with an independent judiciary necessitated the federal judiciary's unique role in being able to invalidate the acts of other branches of government that contravened the Constitution. In contrast to the political branches, the federal judiciary as envisioned by the nation's founding document arguably raised few concerns and was the subject of little debate for the Framers of the Constitution. Records from the Constitutional Convention of 1787 consist of "surprisingly little" on the federal judiciary. Most delegates to the Convention took "for granted" even the seemingly most controversial aspect of the federal judicial power, the power of judicial review. Moreover, the Constitution itself devotes—relative to the other branches—very little attention to the role of the judiciary: less than 500 words. And in the midst of the debate over whether to ratify the Constitution, Alexander Hamilton famously downplayed anti-federalist concerns regarding the power of the federal courts, calling the judiciary the "least dangerous branch" because the judiciary possesses neither the power of the purse, like the legislative branch, nor the power of the sword, like the executive branch. In sharp contrast to the views of the Framers, American history has been replete with examples of outcry at the scope of the powers provided to the unelected federal judiciary. Thomas Jefferson, in the wake of his presidency, disavowed the power of judicial review, arguing that "[e]ach of the three departments has equally the right to decide for itself what is its duty under the constitution, without any regard to what the others may have decided for themselves under a similar question." Andrew Jackson, in vetoing the reauthorization of the Bank of the United States, dismissed the 1819 case McCulloch v. Maryland that upheld the constitutionality of the Bank, contending that "the opinion of the judges has no more authority over Congress than the opinion of Congress has over the judges, and on that point the President is independent of both." In the wake of Dred Scott v. Sandford and its declaration that African Americans had "no rights which the white man was bound to respect," Abraham Lincoln, in his first inaugural address, famously noted that, if the policy of government upon vital questions ... is to be irrevocably fixed by decisions of the Supreme Court ... the people will have ceased to be their own rulers, having ... practically resigned their government into the hands of that eminent tribunal. While modern criticisms of the Court have eschewed explicitly disputing Marbury's central holding, controversies over the power of judicial review have extended into the 20 th and 21 st centuries. In 1935, Franklin Roosevelt prepared a message announcing that he would ignore the Court's decision in the Gold Clause Cases , deterred only by a favorable ruling by the High Court. And the Supreme Court's invalidation of several of the central features of Roosevelt's New Deal spurred the President's infamous "court packing" plan aimed at limiting the power of the Court to invalidate progressive legislation. Two decades later, the Court's decision in Brown vs. Board of Education ending racial segregation in public schools spurred intense backlash against the Court in the South, with one prominent southern Senator going so far as to describe Brown as a "legislative decision by a political court.... " By the late 1960s, Richard Nixon coined the phrase "judicial activism" to describe the constitutional jurisprudence of the Warren Court and pledged to appoint "strict constructionists" to the Court to "restore" a proper "balance," leading some scholars to suggest that Nixon's message in 1968 was centered on the anti- Marbury proposition that it was "not for the Court to be deciding major constitutional issues." And President Obama, following oral argument regarding the constitutionality of the Affordable Care Act, expressed concern that an "unelected group of people" would take the "unprecedented, extraordinary step of overturning a law that was passed by a strong majority of a democratically elected Congress." The Framers' treatment of the judiciary's powers juxtaposed with the political branches' often-fractious relationship with the judiciary illustrates the "root difficulty" with the power of judicial review. On one hand, an independent judiciary is needed to ensure that the core norms of our society, as embodied in the Constitution, are enforced against temporary populist interests. After all, according to Professor Alexander Bickel in his seminal work The Least Dangerous Branch, "when the pressure for immediate results is strong enough and emotions ride high enough," the political branches may "prefer to act on expediency rather than take the long view." In contrast to acting on "expediency," the federal judiciary, per Bickel, acts on "principle" and, therefore, should be expected to be the central governmental actor that, for example, enforces the First Amendment to "protect unpopular individuals from retaliation—and their ideas from suppression—at the hand of an intolerant society." And when the Court opts to shirk its duty to act on "principle" and instead upholds a law that may not in actuality adhere to core constitutional norms, the High Court "legitimates" or validates that law, and, in so doing, risks damage to the basic values undergirding our system of government.