President Trump slammed Justin Amash on Thursday.

President Trump reacted to Representative Justin Amash's decision to leave the Republican Party.  "Great news for the Republican Party as one of the dumbest & most disloyal men in Congress is 'quitting' the Party," Trump tweeted Thursday. "No Collusion, No Obstruction! 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, a five-term congressman, previously broke from his fellow Republicans by calling for Trump's impeachment and saying that Attorney General William Barr mischaracterized the findings of Robert Mueller's investigation.  He announced his severing of ties with the GOP in an op-ed published by the Washington Post hours prior to Trump's tweet.  "Today, I am declaring my independence and leaving the Republican Party," Amash stated in the piece. "No matter your circumstance, I'm asking you to join me in rejecting the partisan loyalties and rhetoric that divide and dehumanize us."