President Trump called Rep. Justin Amash of Michigan “disloyal” and dumb after the lawmaker announced he was leaving the Republican Party in an op-ed published Thursday. “Great news for the Republican Party as one of the dumbest & most disloyal men in Congress is ‘quitting’ the Party. No Collusion, No Obstruction!” Trump wrote in a tweet. “Knew he couldn’t get the nomination to run again in the Great State of Michigan. Already being challenged for his seat. A total loser!” Amash was the only Republican in Congress to publicly back Trump’s impeachment before quitting the party. “Today, I am declaring my independence and leaving the Republican Party,” the former member of the House Freedom Caucus wrote in The Washington Post, adding that he was “rejecting the partisan loyalties and rhetoric that divide and dehumanize us.”