The U.S. Supreme Court heard oral arguments Tuesday in St. Mary Catholic Parish v. Roy, a case testing whether Colorado can require Catholic preschools to admit children of same-sex parents or those identifying as transgender to participate in the state's taxpayer-funded universal preschool program.

The Archdiocese of Denver and two parishes sued after the state refused to exempt them from a nondiscrimination agreement that bars exclusion based on sexual orientation or gender identity. The program provides up to 15 hours of free preschool weekly to eligible families at participating public or private providers.

Catholic plaintiffs, represented by the Becket Fund for Religious Liberty, argued the mandate violates the First Amendment's free exercise clause by forcing them to act against church teachings on marriage, family, and biological sex. They pointed to the court's 2022 Carson v. Makin decision, which barred states from excluding religious schools from generally available funding programs.

Colorado maintained the rules are neutral and generally applicable, applying equally to all providers. The state noted some Catholic Charities preschools participate under the requirements while others do not.

During arguments, the court's conservative majority appeared sympathetic to the religious liberty claims. Justices questioned why the state could not accommodate the archdiocese's beliefs without undermining the program. Liberal justices raised concerns about potential discrimination against families.

A ruling is expected by June 2027. The case builds on a series of Supreme Court decisions expanding protections for religious institutions seeking public benefits while highlighting ongoing tensions between religious exercise and antidiscrimination policies.