In recent decades, the Supreme Court has lost its ability to base its legitimacy solely on its legal expertise yet it has gained public support as a new source to legitimize its authority. Due to growing public understanding that legal expertise does not award the Court with determinate answers, the Court has partly lost expertise as a source of legitimacy. The idea that judges decide salient cases based on their political preferences has become part of common sense and has eroded the Court’s image as an expert in the public mind. On the other hand, as a result of the invention of scientific public opinion polls and their current centrality in the public mind, the Court has now available a new source of legitimacy. Thanks to public opinion polls that measure public support for the Court, the Court for the first time in its history, has now an independent and public metric demonstrating its public support. The monopoly elected institutions had on claiming to hold public mandate has been broken. As a result of these changes as well as the lessons the Court took from the Lochner decisional line and Brown, an important shift in the political balance of power and subsequently in the Rehnquist Court’s understanding of its own sources of legitimacy occurred.