U.S. District Judge Emmet Sullivan of the District of Columbia expects his orders to be followed. It’s an expectation for federal judges in general—but one that has increasingly been defied by the Trump administration.

In a recent series of lawsuits over the postal service’s handling of mail-in ballots ahead of the November presidential election, Sullivan said he had reason to believe officials weren’t acting in line with what he ordered, to the point he said Postmaster General Louis DeJoy may have to appear in court to explain himself.