Monday morning Senator Jeff Flake appeared on MSNBC’s Morning Joe and criticized Donald Trump’s comments about Judge Curiel, saying they were “a whole new level.” Flake also said he could not endorse Trump and might even end up refusing to vote for him unless something changes.

“It’s not just ill-informed or ignorant statements,” Flake told host Joe Scarborough, “but they suggest that when he’s president, you know after November, that perhaps he ought to go after that judge.” Flake added, “That’s a whole new level. It’s very disturbing.”

“What standard is this?” Scarborough asked, after pointing out that Judge Curiel was born in Indiana. Scarborough added, “It’s not American.”

“The whole thing that we Republicans say we’re against, this identity politics, to say that if you’re a certain gender or you’re a certain race that you have to vote that way,” Flake replied. “He’s just trying to confirm that stereotype that’s completely wrong. It’s offensive, it really is,” he added.

Asked if there were reasons Trump should be president, Flake replied, “He’s the nominee. I hope that he changes.” Scarborough interrupted to ask if Flake was ready to endorse Trump. “No…no. It’s uncomfortable not having endorsed the Republican nominee, I have to say,” Flake replied, adding, “But I can’t at this point.” Flake said he could even end up in the same position as Jeb Bush, i.e. refusing to vote for Trump but supporting down-ballot GOP candidates.

Later in the interview Flake was asked if he thought it was possible Arizona could wind up in the Democrats’ column in November. “Yes, I do,” Flake replied. He added, “Right-thinking Republicans want somebody who is serious, for example on immigration reform and saying that we’re going to build a wall and make Mexico pay for it is not a serious proposal.”

“They want serious proposals on how to deal with this war on terrorism. Saying that you’re going to ban Muslims from entering the country is not a serious proposal. So it’s not just Hispanic voters that I’m concerned about, I am concerned about them, but it’s the broader electorate, broader Republicans.”