LAKE BUENA VISTA, Fla.—Supreme Court Justice Clarence Thomas questioned a proposed ethics rule that would discourage federal judges from belonging to the conservative Federalist Society and its liberal counterpart, the American Constitution Society.

Justice Thomas has long participated in events sponsored by the Federalist Society, which has groomed many of President Trump’s judicial nominees.

“And now I think they’re about to silence the Federalist Society. So I guess I can’t come back,” Justice Thomas quipped Friday at Federalist Society convention at Walt Disney World.

“Some of us are fighting back,” responded U.S. Circuit Judge Gregory Katsas, a former Thomas law clerk who interviewed his former boss before the audience.

The ethics proposal, circulated last month by the federal judiciary’s policy-making body, the Judicial Conference of the U.S., would tighten existing guidance that lets judges belong to the two groups but not take leadership roles.