HELENA — Montana U.S. Sen. Jon Tester said Friday he’ll vote against Brett Kavanaugh’s confirmation to the U.S. Supreme Court, removing himself from the short list of undecided Democratic senators who are up for re-election in states won by President Donald Trump.

Tester’s decision is sure to be used as campaign fodder by his Republican opponent, State Auditor Matt Rosendale, and by outside groups like the National Rifle Association, which previously launched an ad campaign against Tester for his last three Supreme Court confirmation votes.

Tester’s announcement came the day after an emotional Senate Judiciary Committee hearing that featured Kavanaugh accuser Christine Blasey Ford describing allegations of the judge’s sexual assault of her when they were teenagers, and Kavanaugh angrily defending himself.

Tester cited Ford’s allegations, which a spokeswoman said the senator found credible and disturbing, and the D.C. Circuit Court of Appeals judge’s record as reasons for his no vote.

“I have concerns that Judge Kavanaugh defended the Patriot Act instead of Montanans’ privacy,” Tester said in a statement. “I have concerns about his support for more dark money in politics. I have concerns about who he believes is in charge of making personal health decisions. And I have deep concerns about the allegations of sexual assault against Judge Kavanaugh.”

Tester had been among a handful of undecided Senate Democrats in tough re-election campaigns, a list that also includes Heidi Heitkamp of North Dakota and Joe Manchin of West Virginia. Republican Sens. Susan Collins of Maine and Lisa Murkowski of Alaska also have not said how they would vote.

A third Republican who had been on the fence, Sen. Jeff Flake of Arizona, cast the deciding vote to send Kavanaugh’s nomination to the Senate floor with the understanding that the FBI would conduct a one-week investigation into the sexual assault allegations before a final vote.

Republicans hold a slim, one-vote majority in the Senate, meaning they would need the help of Democrats to confirm Kavanaugh if two Republicans or more vote no.

Tester’s confirmation vote already had been a flashpoint in his re-election, with Rosendale pointing out that Tester never met with the Trump nominee, and implying that the senator wasn’t giving Kavanaugh a fair shot. Tester has said that he requested a meeting with Kavanaugh several times, but the White House would not commit to a specific date or time.

Rosendale said in a statement that Senate Democrats made the decision to do whatever it takes to keep Kavanaugh off the bench. He called the sexual assault allegations a “smear process.”

“No one should be surprised by this,” Rosendale said of Tester’s decision. “We always knew Jon Tester was never going to vote for Judge Brett Kavanaugh.”

His statement mirrored that of U.S. Sen. Steve Daines, the Republican who will have Montana’s other vote in the Kavanaugh confirmation. Daines said there was no evidence corroborating Ford’s allegations and that Senate Democrats should be ashamed for turning the process into an embarrassing political circus.

“I look forward to casting my vote for Judge Kavanaugh,” Daines said.

Earlier this month, the NRA released a television ad criticizing Tester’s votes against Justice Neil Gorsuch and for Justices Elena Kagan and Sonia Sotomayor, saying the senator sided with the “anti-gun liberal left” on all three confirmation votes.

Republican groups quickly criticized Tester on Friday, saying that he was listening to Senate Democratic leaders instead of his own constituents.

“Now that Tester is voting NO on Judge Kavanaugh, Montanans will be voting NO on Tester in November,” Republican National Committee spokeswoman Miki Carver said in a statement.