CRS Report – Congressional Participation in Litigation: Article III and Legislative Standing Updated November 8, 2019 – Since the founding, the federal courts have played a critical role in adjudicating legal disputes, including ones involving executive action. As the Supreme Court stated in Marbury v. Madison, “where a specific duty is assigned by law . . . the individual who considers himself injured has a right to resort to the laws of his country for a remedy.” To that end, Congress and its Members have occasionally sued the Executive in federal court in an attempt to vindicate their institutional priorities, argue that the Executive is violating their legislative prerogatives, or advance their legislative policy interests. During the Obama Administration, for instance, legislative entities brought or joined litigation in federal court for a host of reasons, such as to challenge the Executive’s decision to allegedly expend money without a congressional appropriation, to defend the Defense of Marriage Act from constitutional challenge after the Executive declined to do so, and to challenge the Executive’s decision to engage in military action in Libya. Likewise, during the Trump Administration, legislators have become involved in lawsuits challenging the President’s alleged unconstitutional acceptance of emoluments, suits demanding the production of documents from the Administration, and a lawsuit seeking to enjoin the executive branch from spending certain funds to build certain barriers along the Mexican border. Congressional interest in litigation likely has increased in salience under the current divided government, as illustrated by the House of Representatives’ resolution to authorize the House to participate in ongoing litigation in Texas involving the Affordable Care Act and a lawsuit brought by several Members of Congress challenging the President’s appointment of an acting Attorney General. However, whenever any party seeks to invoke the power of the federal courts, it must first show that its dispute belongs there. For nearly its entire history, the Supreme Court has emphasized that the role of courts is in “decid[ing] on the rights of individuals.” By contrast, “[v]indicating the public interest (including the public interest in Government observance of the Constitution and laws) is the function of Congress and the Chief Executive.” The federal courts apply a number of doctrines, known as justiciability doctrines, to ensure that judges do not step beyond their bounds and decide issues more properly reserved for the other branches. Foremost among these doctrines is the requirement that a party seeking judicial relief from a federal court demonstrate “standing.” This report provides an overview of the standing doctrine as it applies to lawsuits.”