The latest allegation against President Donald Trump's second Supreme Court nominee, Brett Kavanaugh, is "ridiculous," Republican strategist Sara Fagen told CNBC on Wednesday.

Fagen worked with Kavanaugh during the administration of President George W. Bush. Kavanaugh served as counsel and staff secretary, while Fagen was a senior aide and White House political director.

"It just doesn't add up," Fagen said on "Power Lunch."

The pair worked together for five years, and Fagen said she has socialized with Kavanaugh on many occasions.

"He is a gentlemen. He is respectful, and this just does not line up with the person I know," she added.

A third accuser of Kavanaugh publicly revealed herself on Wednesday. Julie Swetnick alleges that Kavanaugh and others in the early 1980s spiked the drinks of girls at high school parties to make it easier to gang rape them.

Kavanaugh denied the accusation, saying: "This is ridiculous and from the Twilight Zone. I don't know who this is and this never happened."

The bombshell allegations come a day before Kavanaugh is scheduled to testify in front of the Senate Judiciary Committee. His first accuser, Christine Blasey Ford, is also expected to testify that Kavanaugh held her down and tried to tear off her clothes when she was 15.

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Another woman, Deborah Ramirez, has accused Kavanaugh of exposing himself to her and causing her to touch his penis at a Yale dorm party.

Fagen has been outspoken in her support of Kavanaugh, telling CNBC in an interview last week that she believes he's telling the truth when he denies the allegations.

"This has become very political. I don't think any of these women — no matter what happened to them by whom, when, how, what, I don't believe it's Judge Kavanaugh — they've not been well served by this process," she said Wednesday. "They've brought this out at the 11th hour and turned this into a political circus, which is exactly what it's been designed to do."

She also thinks it will energize Republicans to vote in November.

"Republicans now are mad. They feel like Democrats are trying to take the Supreme Court nominee away from them … take him down at whatever cost."

— CNBC's Tucker Higgins, Dan Mangan and Kevin Breuninger contributed to this report.