In an extraordinary display of conflict between the executive and judiciary branches, Chief Justice John Roberts rejected calls for impeaching judges Tuesday, shortly after President Donald Trump demanded the removal of one who ruled against his deportation plans.

The rebuke from the Supreme Court’s leader demonstrated how the controversy over recent deportations of alleged Venezuelan gang members has inflamed tensions over the judiciary’s role, with a legal case challenging Trump’s actions now threatening to spiral into a clash of constitutional powers.

“For more than two centuries, it has been established that impeachment is not an appropriate response to disagreement concerning a judicial decision,” Roberts said. “The normal appellate review process exists for that purpose.”

The rare statement came just hours after a social media post from Trump, who described U.S. District Judge James E. Boasberg as an unelected “troublemaker and agitator.” Boasberg had issued an order blocking deportation flights that Trump was carrying out by invoking wartime authorities from an 18th century law.

“HE DIDN’T WIN ANYTHING! I WON FOR MANY REASONS, IN AN OVERWHELMING MANDATE, BUT FIGHTING ILLEGAL IMMIGRATION MAY HAVE BEEN THE NUMBER ONE REASON FOR THIS HISTORIC VICTORY,” Trump wrote on his social media platform, Truth Social. “I’m just doing what the VOTERS wanted me to do. This judge, like many of the Crooked Judges’ I am forced to appear before, should be IMPEACHED!!!”

Although Trump has routinely criticized judges, especially as they limit his efforts to expand presidential power, his latest post escalated his conflict with a judiciary that’s been one of the few restraints on his aggressive agenda. Impeachment is a rare step that is usually taken only in cases of grave ethical or criminal misconduct.

In an interview with Fox News later on Tuesday, Trump emphasized that Roberts “didn’t mention my name in his statement,” suggesting that the chief justice could have been referring to other people who have said Boasberg should be impeached.