Former White House strategist Steve Bannon called powerful Tennessee Senator Bob Corker “a disgrace” and declared in an appearance on Fox News’ “Hannity” that, “If Bob Corker has any honor, any decency, he should resign immediately.”

Corker has already announced he won’t run for re-election in 2018, and has been opening up more lately in his criticism of President Trump, saying over the weekend that Mr. Trump is treating the presidency like a reality show and making threats that could set the U.S. “on the path to World War III.”

The president tweeted a few insults about Corker over the weekend.

“I said ‘NO’ and he dropped out (said he could not win without my endorsement),” the president claimed in a Sunday morning tweet.

The president also claimed Corker wanted to be his pick for secretary of state. “I said ‘NO THANKS,”‘ he added, then blamed Corker for being “largely responsible for the horrendous Iran Deal.”

Corker responded in a tweet, “It’s a shame the White House has become an adult day care center. Someone obviously missed their shift this morning.”

Bannon told host Sean Hannity, “There’s a coalition coming together that’s going challenge every incumbent except Ted Cruz.” Bannon told Hannity he’s eyeing about 15 races for possible primary efforts.