Heitkamp apologizes for ad that mistakenly identified some women as abuse survivors; misidentified others "I deeply regret this mistake," Sen. Heitkamp said to ABC News in a statement.

North Dakota Democrat Sen. Heidi Heitkamp is apologizing after a newspaper ad released by her campaign used the names of sexual assault survivors who did not give permission for their information to be used and incorrectly identified others.

Heitkamp, who is facing a tough re-election bid in a state President Trump won by 36 points in the 2016 presidential election, said in a statement she recently learned that several women named in the ad hadn’t authorized it or are not survivors of abuse.

“Sexual assault is a serious crime – and one that too many North Dakota women have experienced. In an attempt to bring awareness to this issue and push back against dismissive comments toward sexual assault survivors by Kevin Cramer, our campaign worked with victim advocates to identify women who would be willing to sign the letter or share their story,” Heitkamp explained in a statement provided by her campaign to ABC News.

“We recently discovered that several of the women's names who were provided to us did not authorize their names to be shared or were not survivors of abuse. I deeply regret this mistake and we are in the process of issuing a retraction, personally apologizing to each of the people impacted by this and taking the necessary steps to ensure this never happens again,” Heitkamp said in the statement.

The ad ran on Sunday in several North Dakota newspapers as an open letter to Kevin Cramer, Heitkamp’s Republican opponent in the Senate race, criticizing comments Cramer made during a New York Times interview in which he ripped into the #MeToo movement.

The open letter was signed by more than 125 people.

“That you’re just supposed to believe somebody because they said it happened,” Mr. Cramer said during the New York Times interview, alluding to Christine Blasey Ford — the woman who has accused Justice Brett Kavanaugh of sexually assaulting her when they were teenagers – and further challenging more broadly the idea of believing sexual assault survivors.

He also referenced the women in his family, claiming "they cannot understand this movement toward victimization."

"They are pioneers of the prairie," he said. "These are tough people whose grandparents were tough and great-grandparents were tough."

Heitkamp’s ad was a direct response to these comments.

“We are here to let you know what prairie tough looks like. We are here to let you know that you are wrong – this is not “a movement toward victimization” it’s about being a survivor. We are here to let you know that we have all suffered from domestic violence, sexual assault, or rape – and that yes, we expect somebody to believe us when we say it. Because it happened,” the open letter began.

Heitkamp voted no on Kavanaugh’s nomination. Cramer supported Kavanaugh.

Cramer called his opponent’s ad a “revictimization of victims.”

“This is what happens when desperate people do things for their own personal political gain,” Cramer told the Associated Press. “She proved a point that her personal politics matter more than someone’s personal pain.”

"This is another example of Heidi Heitkamp exploiting whoever she can for political gain," said Jake Wilkins, communications director for the North Dakota Republican Party in a statement to ABC News. "With a campaign built on lies, misinformation, and manufactured controversy, it’s no wonder Heitkamp is the most vulnerable Senator in the country."

Late Wednesday, Heitkamp's communications director told ABC News: "Sen. Heitkamp asked for the person responsible for the ad to resign and that person resigned."