As the judicial and legislative branches have taken a more passive approach to civil rights enforcement, the President’s exercise of independent, extrajudicial constitutional judgment has become increasingly important. Modern U.S. presidents have advanced constitutional interpretations on matters of race, gender, HIV-status, self-incrimination, reproductive liberty, and gun rights, and President Obama has been especially active in promoting the rights of lesbian, gay, bisexual, and transgender (LGBT) persons—most famously by refusing to defend the Defense of Marriage Act (DOMA). Commentators have criticized the President’s refusal to defend DOMA from numerous perspectives but have not considered how the President’s DOMA policy fits within a principled commitment to LGBT equality that includes supporting and signing legislation, pursuing regulatory initiatives, filing complaints and other court papers, making formal and informal choices in law enforcement, and using the bully pulpit to sway public opinion. The President’s nondefense of DOMA not only derives normative force from his larger vision regarding substantive equality and individual rights, but it also demonstrates how certain features of the presidency—including accountability and expertise—can be instrumental in promoting equality-based claims. In this way, presidential constitutionalismcan engage coordinate institutions—including the Supreme Court—in the development of constitutional law.