WASHINGTON — Sen. Lindsey Graham has rarely held back in his criticism of Ted Cruz, but the South Carolina Republican said his endorsement of Cruz on Thursday shows what he's willing to do to try to save the party from Donald Trump.

"This is an odd moment," Graham told a few reporters in the Senate. "I'll be the first to say it. It's an odd alliance, but it's an alliance I feel comfortable with given my choices."

Graham will be hosting a fundraiser for Cruz in Washington on Monday on the sidelines of the pro-Israel group AIPAC's conference. Earlier this year, Graham described picking between Trump and Cruz as a choice between "being shot and poisoned."

"The bottom line is that I'm very passionate about my nation," Graham said on Thursday. "I'm very passionate about my party. People can take what I say with a grain of salt, but I've come to conclude that Mr. Trump is not a Republican. He's an interloper. That he's jumped into this race and it's all about Trump. His foreign policy is gibberish. He's appealing to our darker side and Ted Cruz is a much more reliable Republican than Donald Trump."

"On the positive side with Ted, I do think he's a good friend of Israel, that he would repeal and replace Obamacare, and he would pick a reliable conservative to be on the Supreme Court."

Graham added that although Republicans might lose in 2016 with Cruz as the nominee at least the party won't be destroyed.

"If we give the banner of the Republican Party to Donald Trump, we tarnish it maybe forever. That might be the end of the Republican Party as I know it. We could lose in 2016 and still be a viable party. If we nominate Donald Trump, I don't think if we're a reliable party in terms of conservatives anymore."

Graham said he didn't talk to John Kasich before making his decision because he's convinced the Ohio governor doesn't have a path to the nomination.

"Do I think Ted Cruz is the most electable person? No, I think John Kasich is more electable... Ted's going to be the most viable alternative. I see him as the best able to stop Trump and get to 1,237. It is an outsider year. John Kasich is good governor and a great friend. I wish he could do better, but it's not John's fault."