Washington (CNN) Sen. Heidi Heitkamp of North Dakota -- a red state Democrat who had been an undecided vote -- announced Thursday that she will oppose Judge Brett Kavanaugh's nomination to the Supreme Court.

North Dakota station and CNN affiliate WDAY first reported the decision by releasing an exclusive video clip of an interview with the senator where she says, "I will be voting no on Judge Kavanaugh."

Heitkamp, who is up for re-election this fall in a state President Donald Trump won overwhelmingly in 2016, later released a statement announcing her opposition.

"After doing my due diligence and now that the record is apparently closed, I will vote against his confirmation," she said.

The senator cited Christine Blasey Ford, who accused Kavanaugh of sexually assaulting her in the early 1980s, in her statement, saying, "When I listened to Dr. Ford testify, I heard the voices of women I have known throughout my life who have similar stories of sexual assault and abuse."

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