This GOP Senator Still Can't Bring Himself To Endorse Donald Trump

While many Republicans who previously hesitated to support Donald Trump  have given in, Arizona Sen. Jeff Flake remains one of the few GOP holdouts , affirming on Monday that he "can't at this point" support his party's presumptive presidential nominee.

“It’s uncomfortable not having endorsed the Republican nominee, I have to say. But I can’t at this point. I hope to be able to support the nominee. I certainly can't right now," Flake said on MSNBC 's "Morning Joe."

Flake is particularly concerned about Trump's racist and anti-immigrant rhetoric. He said that Trump's attacks on a federal judge presiding over a fraud lawsuit against the now-shuttered Trump University reached "a whole new level." 

But like many in his party, Flake is hopeful that Trump will moderate his rhetoric  for the general election.

“He was not my first choice nor my 17th choice,” Flake said. “He's the nominee, and we'll have to deal with that. I hope that he changes.”

So far Trump has shown no signs of change, as evidenced by his doubling down on his slurs against U.S. District Judge Gonzalo Curiel's integrity. Last week, the real estate mogul claimed that the judge must be biased against him  because the judge is "of Mexican heritage." Over the last few days, Trump has continued that attack , despite handwringing among top Republicans as well as his campaign advisers.

Flake warned that Trump's rhetoric could have electoral consequences in the senator's home state of Arizona, where Latino voters are a growing political constituency. Nationally, Trump has abysmally low ratings among Latino voters.

The senator also blasted Trump's policy positions, saying that GOP voters need someone with "serious proposals."

"'We're going to build a wall and make Mexico pay for it' is not a serious proposal," Flake said. "They want serious proposals on how to deal with this war on terrorism. Saying that you're going ban Muslims from entering the country is not a serious proposal."

Editor's note: Donald Trump regularly incites political violence and is a serial liar , rampant xenophobe , racist , misogynist and birther who has repeatedly pledged to ban all Muslims -- 1.6 billion members of an entire religion -- from entering the U.S.