Sen. Ben Sasse (R-NE) lost at least one supporter because of his tweet calling out the President for “recanting” his oath of office on Twitter Wednesday: Sean Hannity.

Retweeting Sasse’s message to the President — in which Sasse criticized President Donald Trump for attacking the freedom of the press — Fox News host Sean Hannity said supporting Sasse was “one of the biggest mistakes in my career” and called him “useless.”

One of the biggest mistakes in my career was supporting @BenSasse Just useless. https://t.co/bYReWFdfKO — Sean Hannity (@seanhannity) October 12, 2017

Sasse shot back, saying Hannity “changed, not me” and that “some of us still believe in the Constitution.”

Sorry, Sean — you changed, not me. Some of us still believe in the Constitution. No President should play with censoring news they dislike. https://t.co/ZBEMNSF7nz — Ben Sasse (@BenSasse) October 12, 2017

Hannity, a vocal supporter of Trump, responded with a series of tweets, saying he’d “never support censoring anybody!!” and calling Sasse a “#Loser” for not repealing Obamacare.

I’d never support censoring anybody!! I’ve stood up for freedom of speech/Constitution my entire life. You have accomplished NOTHING IN DC. https://t.co/H2T262MOxc — Sean Hannity (@seanhannity) October 13, 2017

The @POTUS keeps his promises. You criticize the Potus daily. How about standing up to McConnell? Call me when u repeal Obamacare #Loser https://t.co/H2T262MOxc — Sean Hannity (@seanhannity) October 13, 2017

Also Ben if you care so much about the Constitution, where have you been on surveillance, unmasking, leaking raw intel? 4 th amendment? https://t.co/H2T262vd8C — Sean Hannity (@seanhannity) October 13, 2017

And Ben In New York Times v. Sullivan, “false statements” with “actual malice” are not protected by the Constitution,Hmm “Fake News” Malice? https://t.co/H2T262vd8C — Sean Hannity (@seanhannity) October 13, 2017

Sasse’s initial statement comes after Trump suggested that “Fake News” outlets should have their broadcasting licenses “challenged” or even “revoked.”

Trump’s irritation has been aimed at NBC News this week, after it published exclusive stories about Secretary of State Rex Tillerson wanting to resign this summer and calling Trump a “moron.”