‘Bob has big plans’: GOP Sen. Corker’s feud with Trump fuels speculation of impeachment
Sen. Bob Corker and President Donald Trump

Sen. Bob Corker (R-TN) fired back at President Donald Trump on Sunday morning, and their Twitter feud fueled speculation the outgoing senator may call for impeachment.

The Tennessee Republican announced last month that he would not seek re-election next year, and the former Trump defender has criticized the president's temperament and fitness for office.

Trump attacked the 65-year-old Corker on Twitter, claiming the senator had begged for his endorsement and decided to drop out after the president refused.

Corker responded an hour later by insulting the president's maturity.

"It's a shame the White House has become an adult day care center," Corker tweeted. "Someone obviously missed their shift this morning."

Corker, who had been considered a candidate to serve as Trump's secretary of state, strongly questioned the president's stability and competence after his moral equivocation on the white supremacist rally in Charlottesville.

That criticism, and his decision to leave the Senate when his second term ends, prompted speculation that he might lead the Republican charge to impeach Trump.

Corker's insult Sunday morning only added to that speculation.

Even if Corker's not planning to lead a drive for impeachment, many questioned the wisdom of attacking his own party's lawmakers in a closely divided Senate.