The Federalist Society for Law and Public Policy Studies was founded in 1982 by law students at Yale, Harvard, and the University of Chicago with support from conservative foundations. It grew into the primary professional network and vetting organization for conservative and libertarian legal talent. Under Leonard Leo's leadership, the Federalist Society effectively controlled Republican judicial selection from the Reagan administration through Trump's first term, helping to place 234 judges including three Supreme Court justices. Trump publicly broke with the organization in 2025, accusing it of producing judges who ruled against him. The split marked a historic division between judicial philosophy conservatism and MAGA political loyalty.