Monday on CNN’s “New Day,” CNN political commentator Jason Miller, the former communications director for Donald Trump’s presidential team, weighed in on the public back-and-forth that has taken place between President Donald Trump and Sen. Bob Corker (R-TN) over the past few days.

That feud escalated on Sunday between the two in a Twitter exchange, and according to Miller, it seems to be a result of Corker’s announcement last month that he would not seek re-election to the U.S. Senate.

“I think it is important to point out Senator Corker has been attacking the president over the last couple of months here,” Miller said. “And obviously the president took issue with that. Look, Senator Corker definitely didn’t mind kissing up to President Trump when he wanted to be vice president when he wanted to be secretary of state. But now since he didn’t get either of these positions, and now he’s retiring, he seems to just be kind of letting it all hang out there. And I think it’s really showing the true colors of the swamp nature of Washington, D.C. that he is criticizing such basic tenets of the Republican platform like tax cuts.”

Miller suggested that given Corker’s newfound willingness to criticize the Trump and his reluctance to support his agenda, Corker should step aside and allow Gov. Bill Haslam (R-TN) to appoint Rep. Marsha Blackburn (R-TN), who announced she would seek that seat in the U.S. Senate last week.

“And look, if Senator Corker is retiring and he doesn’t want to be in the U.S. Senate, and he doesn’t want to support President Trump, and he doesn’t want to support such basic conservative principals, he should just resign. Let the governor of Tennessee go and appoint a conservative like Marsha Blackburn, the congresswoman who is running to replace Senator Corker and get someone in there who is actually going to support the president.”

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