Anthony Scaramucci escalated his feud with President Donald Trump on Monday, urging the GOP to "call in a good relief pitcher" and replace Trump as the party's nominee after a series of political maelstroms involving race.

The short-lived former White House communications director and GOP donor warned that former Vice President Joe Biden could beat Trump in the 2020 election. He told MSNBC's Stephanie Ruhle that the Republican Party needs to drop Trump after his "racist tweets" over the past few weeks and his handling of recent mass shootings, one of which targeted Latino immigrants and is being investigated as domestic terrorism.

"Do they have the courage to step forward in a block and knock this guy off? If they do, then I think it will be a very fun race and I think that the Republicans will win. If they don't, he's stuck at 42 percent, if [Democrats] put up someone like Joe Biden, it's going to be very tough in Michigan and places like Pennsylvania," he said. He noted that he would not vote for a Democrat, though.

Trump remains deeply popular with Republican voters. A recent Gallup poll shows that the president has an 88 percent job approval rating among GOP voters. However, the president is vulnerable among the general population, with only 42 percent of Americans approving of his job performance. Former Massachusetts Gov. Bill Weld is the only Republican to announce plans to challenge Trump for the 2020 nomination.

Scaramucci served as White House communications director for less than two weeks in 2017 and continued to defend him in the two years since he was fired. In recent weeks, he has become vocally critical of the president, in particular, his "racist tweets, including telling congresswomen of color to go back where they came from."

Trump shot back on Twitter on Sunday, calling Scaramucci unqualified.

Scaramucci responded to the president‘s attack, telling MSNBC on Monday that, "I can't think of anything less American than bullying people and using your Twitter feed to call out our fellow citizens on Twitter."

Scaramucci, who like so many others had nothing to do with my Election victory, is only upset that I didn’t want him back in the Administration (where he desperately wanted to be). Also, I seldom had time to return his many calls to me. He just wanted to be on TV! — Donald J. Trump (@realDonaldTrump) August 12, 2019

Hours later, the president took to Twitter again to assail his former aide, calling him a desperate and disgruntled former employee who "just wanted to be on TV!"

Scaramucci shot back with an elaborate baseball metaphor.

You are losing your fastball— very weak troll. Bullying is the most anti-American thing in our culture and it is emanating from the Oval Office. Many have called and are willing to work on a necessary replacement. Time to call in a good relief pitcher. @potus is lost. https://t.co/7fiFHbd7O6 — Anthony Scaramucci (@Scaramucci) August 12, 2019

"Time to call in a good relief pitcher," he said.