President Trump escalated his confrontation with the judicial branch today by demanding the impeachment of a federal judge who had ordered the administration to halt its plan to deport more than 200 migrants. The president called the judge, James Boasberg, a “Radical Left Lunatic” and insisted on his removal. Soon after, a Trump ally in Congress filed articles of impeachment against the judge.

The attacks against Boasberg — a centrist Democrat who lived with Justice Brett Kavanaugh while they were at Yale Law School — prompted John Roberts, the chief justice of the Supreme Court, to issue a rare public rebuke.

“For more than two centuries,” Roberts said, “it has been established that impeachment is not an appropriate response to disagreement concerning a judicial decision.”

Around the same time, lawyers for the Trump administration continued their aggressive pushback against Boasberg’s ruling, which barred the U.S. from deporting people suspected of belonging to a Venezuelan street gang under a statute called the Alien Enemies Act. They complied only in part with Boasberg’s instructions to provide data on the deportation flights, which had not yet landed when the judge ordered them to turn around.