J. Scott Applewhite / AP

Sen. Bob Corker unloaded on President Trump during a CNN interview today, stating that Trump will be most remembered for "the debasement of our nation." Corker also said that he "would not" support Trump again, though he stopped short of saying that Trump should be removed from office.

Don't forget: Trump is heading to Capitol Hill for a Senate Republican policy lunch in a few hours. Corker will be in attendance.

Their backstory

Back in April 2016, Corker stopped short of explicitly endorsing Trump, instead telling CNN that he'd made a "really good transition in the campaign." But the lack of a full-throated endorsement didn't stop Corker from being floated as Trump's running mate or secretary of state.

The Tennessee senator was also quick to criticize the administration after reports that Trump had accidentally disclosed classified intelligence to top Russian officials during an Oval Office meeting in May, saying that Trump's White House was in a "downward spiral." And after Trump's botched response to the Charlottesville violence, he told local Chattanooga website Nooga that Trump "has not yet been able to demonstrate the stability nor some of the competence that he needs to demonstrate in order to be successful."

However, it was Corker's September 14 announcement that he would not be seeking reelection to the Senate in 2018 that fully allowed him to open up against the president. In October, he told reporters that the group of Chief of Staff John Kelly, Secretary of State Rex Tillerson, and Defense Secretary John Mattis "separate our country from chaos." Later that week, Trump blasted Corker on Twitter, stating that Corker's comments were precipitated by Trump's refusal to endorse Corker in his upcoming Senate race. Corker then responded with his infamous retort that "the White House has become an adult day care center."

What happened today:

How it all kicked off: Corker appeared on both NBC News' TODAY and ABC News' Good Morning America earlier this morning, where he doubled down on his comments earlier this month that the White House is an "adult daycare center," adding, "I don't make comments I haven't thought about."

Trump responded on Twitter: President Trump continued his attacks against Tennessee Sen. Bob Corker via Twitter this morning: "Bob Corker, who helped President O give us the bad Iran Deal & couldn't get elected dog catcher in Tennessee, is now fighting Tax Cuts....Corker dropped out of the race in Tennesse when I refused to endorse him, and now is only negative on anything Trump. Look at his record!

Corker's fired back on Twitter just before his CNN interview: "Same untruths from an utterly untruthful president. #AlertTheDaycareStaff"

Trump responded to the CNN interview, again via Twitter: "Sen. Corker is the incompetent head of the Foreign Relations Committee, & look how poorly the U.S. has done. He doesn't have a clue as the entire World WAS laughing and taking advantage of us. People like liddle' Bob Corker have set the U.S. way back. Now we move forward!"

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