Article III of the Constitution established the judicial branch of the United States, staffing the branch with life-tenured and salary-protected judges. Amongst the powers of the federal judiciary is the power of "judicial review"-that is, the power to invalidate the acts of other branches of government and the states that contravene the Constitution. The Framers of the Constitution established this "countermajoritarian" role for the judiciary to help protect the written Constitution and its principles against incursions from the political branches. The power of judicial review is both a potent and controversial power, as American history has been replete with examples of outcry at when unelected federal judges invalidate the acts of a democratically elected branch of government. The potential for backlash to judicial review by the political branches has resulted in what late Professor Alexander Bickel termed a "countermajoritarian difficulty," as the judiciary is needed to protect the basic principles of the Constitution, but is also necessarily dependent on the political branches to enforce the judiciary's mandates. In other words, judicial review, while necessary to protect the mandates of the Constitution, is inherently antidemocratic, risking an erosion of the judiciary's role in the American constitutional form of government.