Recent Supreme Court opinions have upended laws that prohibited state support for and participation in devotional exercises, sectarian activities, and religious education. The Essay reviews a variety of historical antecedents that the Court formerly found highly persuasive to Establishment Clause jurisprudence. It next evaluates and critiques the Roberts Court’s steady devaluation and erosion of disestablishment norms in opinions that struck down restraints on prayers at public school events and restrictions on public funding of religious schools. References to history and tradition in those cases are at best oblique and at worst misleading. Rather than formalistic recitations of the strict scrutiny test that exaggerate free exercise concerns, the Court should rely on nuanced contextual reasoning to protect the exercise of private religious convictions and maintain separation between religious beliefs and state actions.