Graham: GOP will get 'slaughtered' if Trump nominee

Sen. Lindsey GrahamLindsey Olin Graham Senate Democrats pump brakes on new stimulus checks Comey, Rice, Clapper among GOP senator's targets for subpoenas amid Obama-era probe Schumer: GOP should 'stop sitting on their hands' on coronavirus bill MORE (R-S.C.) argued Wednesday that if Donald TrumpDonald John Trump Minneapolis erupts for third night, as protests spread, Trump vows retaliation Stocks open mixed ahead of Trump briefing on China The island that can save America MORE is the GOP nominee, Republicans will get "slaughtered" in the November election.

Lambasting the outspoken Republican front-runner as an "opportunist," Graham argued that Trump would kneecap Republicans' hopes of winning back the White House.

"I think he's a kook. I think he's crazy. I think he's unfit for office," Graham, a backer of Trump rival Jeb Bush, said on Fox News's "America's Newsroom."

"I'm a Republican. and he's not. He's not a conservative Republican, he's an opportunist," Graham said on the program. "He's not fit to be president of the United States."

Donald Trump is not a conservative Republican. He's an opportunist. He's not fit to be President of the United States.
— Lindsey Graham (@LindseyGrahamSC) February 17, 2016

If Donald Trump is the GOP nominee for President, we will get slaughtered in November 2016. And frankly, we will deserve it.
— Lindsey Graham (@LindseyGrahamSC) February 17, 2016

Trump pushed back against the broadside, sending several tweets arguing that Graham had no support before ending his own White House bid in December and "no cred" to make the claims.

"I will beat Hillary easily," Trump insisted in one of his tweets before going after Fox News for airing remarks from one of his critics on the program.

Trump is battling several rivals, including Bush, Marco Rubio