Sen. Heidi Heitkamp, D-N.D., was ready to vote to confirm Brett Kavanaugh. Her office had started drafting a statement saying she would support President Donald Trump’s Supreme Court nominee, she told CNN.

And then she watched Kavanaugh unleash partisan attacks during his defiant testimony before the Senate Judiciary Committee. Heitkamp said she listened to Kavanaugh’s exchange with Sen. Amy Klobuchar, D-Minn., who asked the judge whether he had ever been in a drunken blackout. Kavanaugh threw the question back, saying, “I don’t know. Have you?” to the senator.

Heitkamp watched the hearing again, she told CNN’s Dana Bash. This time, with the volume turned off.

“We communicate not only with words, but with our body language and demeanor,” she said. “I saw somebody who was very angry, who was very nervous. … I saw rage.”

Kavanaugh’s performance changed everything, Heitkamp said.

On Saturday, she voted against Kavanaugh, the most consequential vote she had cast to date in her Senate career. The judge’s “temperament, honesty and impartiality” had been called into question, said Heitkamp, who had voted last year to confirm Neil Gorsuch, Trump’s first Supreme Court nominee.

And now, the first-term Senate Democrat, who won the solidly red North Dakota by a 1-percentage-point margin in 2012, is fighting for her political future. Some polls show her trailing by double digits against Rep. Kevin Cramer, R-N.D., a congressman who questioned whether the sexual assault accusation against Kavanaugh was disqualifying even if it were true.

Christine Blasey Ford alleged that Kavanaugh groped her, pinned her down on a bed and tried to stifle her screams during a house party in Maryland in 1982, when the two were in high school. Even if Ford’s allegation is true, “there was no type of intercourse or anything like that,” Cramer told a North Dakota television station last month.

Cramer, whom the president supports, has sought to paint Heitkamp as someone who chose party over the people she represents.

Speaking at an event in Wyndmere, N.D., a few miles from her hometown, Heitkamp told supporters that the past week had been tough for her.

“The political rhetoric is you can’t vote that way if you expect to come back,” she said. “And I tell people — Ray and Doreen Heitkamp didn’t raise me to vote a certain way so that I could win. They raised me to vote the right way.”

She told CNN: “If someone like me can’t get re-elected, what does that speak for people who want to be moderate or just encourage people to go to their base. … I think that’s a real concern.”