President Donald Trump ripped Sen. Bob Corker on Tuesday morning after the Tennessee Republican criticized the President's involvement in Capitol Hill tax negotiations.
The exchange between the two men escalates a public feud that has highlighted divisions between Trump and several Republican lawmakers on Capitol Hill. And it comes on a day when Trump is visiting Capitol Hill for high-stakes discussions about tax reform, threatening to send the President off-message at a critical time for his agenda.
Corker, later asked by CNN's Manu Raju if he should have backed Trump's presidential campaign, said he "would not do that again." He also said Trump has "great difficulty with the truth."
In a series of tweets, the President accused Corker of fighting tax cuts and called him a "lightweight." Corker responded by again likening the White House staff to a "daycare center."
"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....," Trump tweeted. "...Corker dropped out of the race in Tennessee when I refused to endorse him, and now is only negative on anything Trump. Look at his record!"
Corker soon responded on Twitter: "Same untruths from an utterly untruthful president. #AlertTheDaycareStaff."
Trump quickly responded by calling Corker a "lightweight."
The President has previously claimed Corker sought his endorsement, which Corker's office has denied, and the "day care" comment refers to criticism the Tennessee senator levied at Trump earlier in the month.
Corker had criticized Trump during appearances on several television shows Tuesday morning ahead of the President's day on Capitol Hill.
On NBC, Corker called Trump's effort to court senators over the White House's tax reform proposal "a photo-op." And speaking to ABC, he suggested that the President butt out of the process.
"(I)f you start taking things off the table before you get started you make that very difficult. So what I hope is going to happen is the President will leave this effort, if you will, to the tax writing committees and let them do their work and not begin taking things off the table that ought to be debated in the committees at the proper time," he said on "Good Morning America."
When asked if the President is a national security threat, Corker told NBC that he needs to be contained by members of his Cabinet; namely, Secretary of Defense James Mattis, Secretary of State Rex Tillerson, and White House chief of staff John Kelly.
Both Trump and Corker -- who was once in consideration to become Trump's secretary of state -- have publicly bickered following the Tennessee senator's announcement earlier this month that he would not be seeking a third term in the Senate.
Trump attacked Corker via Twitter at the time, saying he denied the senator's request for an endorsement -- a claim denied by Corker's office. In response, Corker said, "It's a shame the White House has become an adult day care center. Someone obviously missed their shift this morning."
In remarks to a New York Times story published a short time later, Corker said Trump was treating the presidency like "a reality show," making reckless threats against other countries that put the United States "on the path to World War III."