It's now incontrovertible that Supreme Court Justice Brett Kavanaugh was the victim of at least one—and probably two—false allegations of sexual assault.

The latest evidence comes from Judiciary Committee Chairman Sen. Chuck Grassley (R–Iowa), who has asked the Justice Department to investigate Judy Munri-Leighton, a left-leaning activist from Kentucky, for allegedly making false statements. According to Grassley, Munri-Leighton initially claimed in an email to the committee that Kavanaugh had raped her, and he was questioned on this point during the September 26 hearing regarding allegations made by Christine Blasey Ford and others.

Subsequently, Munri-Leighton recanted her charge and admitted she had never met Kavanaugh. "I was angry, and I sent it out," she said.

Munri-Leighton's confession means this accusation should be definitively labeled false.

Another accusation, made by Julie Swetnick and attorney Michael Avenatti, should be regarded as highly suspect, at the very least, given that the accuser has contradicted her story. (Both Swetnick and Avenatti were referred for investigation as well.) Avenatti supplied NBC News with a witness who supposedly could corroborate Swetnick's account; instead, the woman confessed she felt Avenatti had "twisted" her words. NBC felt cheated; Chuck Todd accused Avenatti of purposefully misleading reporters.

We can't say for certain whether Ford's accusation against Kavanaugh was true, false, or somewhere in-between. But it's simply a fact that several subsequent allegations of sexual abuse have, to varying degrees, collapsed.

This has not deterred some activist groups. "We still believe Julie Swetnick," tweeted Planned Parenthood and NARAL.

The ludicrousness of the progressive slogan that all self-described victims should be believed is on full display. It does survivors of sexual assault no good to take charlatans seriously or to pretend that liars don't exist. When pressure groups or the press claim otherwise, they only undermine their credibility, ensuring that the public will be more inclined to doubt future victims whose stories are embraced by these institutions. As The Washington Post's Megan McArdle writes:

It would, of course, be much simpler if women never lied about rape. Their stories wouldn't need to be interrogated, no sifting and sorting of the facts in a crime that is notoriously hard to prosecute. But we know that's not possible. High-profile false rape accusations such as the ones in the Rolling Stone article reflect the reality that between 2 and 10 percent of rape allegations are provably false; the FBI says 8 percent of forcible-rape allegations are "unfounded." The number of false accusations that can't be proved false necessarily pushes that number even higher. To act as if this weren't the case borders on wishful thinking, and it comes at a cost. NBC wasn't the only media outlet that seems to have relaxed its normal standards during the Kavanaugh hearings. The New Yorker, with exceptionally weak evidence, ran allegations of his sexual misbehavior in college. The reporters no doubt believed they were making it easier for victims to be heard. But airing insufficiently vetted allegations encourages the public to distrust the media. Actual victims won't be heard if no one's listening.

The Kavanaugh fiasco should serve as a strong reminder that the press must cautiously vet accusations, and that legal systems should operate in accordance with principles of fairness and a respect for due process.