President Donald Trump has chosen Brett Kavanaugh for Anthony Kennedy’s seat on the United States Supreme Court, so his record is going to be pawed over and scrutinized. One claim: That Kavanaugh once called Hillary a, excuse the language, bitch.

But is it true? Did Brett Kavanaugh call Clinton the “B” word?

Here’s what you need to know:

The Claim Derives From a Book by David Brock, a Former Conservative Turned Clinton Booster

Judge Brett Kavanaugh is at or near top of SCOTUS list, per several people close to President Trump. But oppo research for possible hearings already moving fast. Sources pt'ing to David Brock's book "Blinded by the Right." Kav alleged to have mouthed an expletive re HRC. Pg. 306. pic.twitter.com/k10MbCm4RR — Robert Costa (@costareports) July 2, 2018

Robert Costa, national political reporter for The Washington Post, gave the claim new life by tweeting about it as Trump was considering Supreme Court candidates. You can read the passage from David Brock’s book about the offending word above. It claims that Kavanaugh “mouthed” the word in 1997 at a private gathering at the home of Fox News host Laura Ingraham.

The book is for sale on Amazon.com.

However, conservatives are unlikely to give the claim much weight as Brock turned his backs on the GOP and made a name for himself by doing it. His book blurb on Amazon reads, in part, “In a powerful and deeply personal memoir in the tradition of Arthur Koestler’s The God That Failed, David Brock, the original right-wing scandal reporter, chronicles his rise to the pinnacle of the conservative movement and his painful break with it.”

David Brock, it says, “pilloried Anita Hill in a bestseller. His reporting in The American Spectator as part of the infamous ‘Arkansas Project’ triggered the course of events that led to the historic impeachment trial of President Clinton. Brock was at the center of the right-wing dirty tricks operation of the Gingrich era–and a true believer–until he could no longer deny that the political force he was advancing was built on little more than lies, hate, and hypocrisy.”

Some conservatives are already downplaying the anecdote.

.@costareports reports oppo researchers digging dirt on possible SCOTUS nom Brett Kavanaugh. The dirt: David Brock says Kavanaugh once, 21 years ago, mouthed the word 'bitch' upon seeing Hillary Clinton on TV. Now, that's a scandal. From 2016: https://t.co/a8SdOL7rHj pic.twitter.com/z0rYISKw9a — Byron York (@ByronYork) July 2, 2018

In 2017, The Nation called Brock “the darling of Democratic Party millionaires and billionaires.” The site reported, “Brock’s empire, including Media Matters, American Bridge, ShareBlue, and Citizens for Responsibility and Ethics in Washington, served as a hit squad for the Clinton campaign last year. Now that Clinton has lost, Brock is retooling his machine to lead the attack on all things Trump.”

Kavanaugh has a long history of tangling with the Clintons, however.

Brett Kavanaugh Was a Principal Author of the Starr Report Who Argued for Broad Impeachment Powers

Brett Kavanaugh was indeed front-and-center in the investigations into former President Bill Clinton over sexual harassment and his honesty about a relationship with an intern, Monica Lewinsky. Some see salience in some of the Starr Report’s arguments at the time over what was allowable grounds to impeach a president.

Kavanaugh was a “lead author” of Ken Starr’s report into Bill Clinton, according to Politico. Kavanaugh, a graduate of Yale University, also worked in the George W. Bush administration and clerked for Anthony Kennedy, before he was named by Bush to the federal bench.

Kavanaugh, now a federal judge, served in George H.W. Bush’s administration in the solicitor general’s office, which is how he became acquainted with Ken Starr. “Kavanaugh was a protegé of Kenneth Starr,” reports Vox. “He was a principal author of the Starr Report.”

Kavanaugh once argued for broad impeachment powers against a president, according to The New York Times, which reported that he thought a president should be impeachable for “lying to his staff and misleading the public.” Those arguments appear in the Starr Report, The Times reported. In 1998, Clinton was, in fact, impeached.

Brett Kavanaugh Later Had a Change of Heart & No Longer Believes Sitting Presidents Should Be Investigated or Charged

You can see what Brett Kavanaugh wrote on the question of presidential investigation and indictment here. In 2009, he wrote a journal article in which he said he had a change of heart and no longer thinks that sitting presidents should be subjected to civil procedure or criminal prosecution and investigation, calling it too distracting considering the seriousness of the job.