“I do not anticipate voting for her this fall,” Susan Collins, the Republican senator from Maine, said of Hillary Clinton. But “I’m not going to say never.” PHOTOGRAPH BY J. SCOTT APPLEWHITE / AP

This week, after Donald Trump said that Gonzalo Curiel, the federal judge in a case against Trump University, had a conflict of interest because of his Mexican heritage, many Republicans distanced themselves from Trump and condemned the candidate's remarks.

House Speaker Paul Ryan said that Trump’s statement was “the textbook definition of a racist comment.” Senator Lindsey Graham, of South Carolina, said that it was “the most un-American thing from a politician since Joe McCarthy,” and that Republicans who previously backed Trump should rescind their endorsements. One Republican senator, Mark Kirk, of Illinois, followed Graham's advice and took back his support, on Tuesday. Congressman Bill Flores, of Texas, who chairs the Republican Study Committee, a House policy group with a large membership, said that he wasn’t prepared to endorse Trump. "I was incredibly angry to see Mr. Trump question a judge's motives because of his ethnicity," Flores said in a statement.

But no matter how much they have condemned Trump, none of these high-ranking Republicans have said that they would consider supporting his Democratic opponent, Hillary Clinton.

In an interview with me, on Wednesday, Senator Susan Collins, of Maine, made herself the exception. Collins told me that Trump’s comment about Curiel was “an order of magnitude more serious” than anything he had previously said, including his “troubling insults towards individuals” and “his poorly-thought-out policy plan about banning Muslims from entering this country."

She added that she was faced with an unprecedented political decision and had to keep all options open. "This is a difficult choice, and it’s one, like many of my colleagues, that I am struggling with," Collins said. "It’s not like we have perfect candidates from whom to choose in this election."

Collins went on to say that she has not ruled out supporting Clinton. “I worked very well with Hillary when she was my colleague in the Senate and when she was Secretary of State,” Collins said. “But I do not anticipate voting for her this fall. I’m not going to say never, because this has been such an unpredictable situation, to say the least.”

I pressed Collins to make sure that she was leaving open the possibility of backing the Democratic Party's presumptive Presidential nominee over Trump. "That is true," Collins, who has been a lifelong Republican, said. "But I do want to qualify that by saying it is unlikely that I would choose to vote for the Democratic candidate."

The Collins interview is part of an article about Trump and the G.O.P. that will appear in the June 20th issue of The New Yorker and will be posted online Monday.