Ed Klein’s newest book on Hillary Clinton, Guilty as Sin, was released this week — and mainstream media critics are trying to discredit both the book and its author with vitriolic, ad hominem, even profane attacks.

Olivia Nuzzi of the Daily Beast, for example, wrote that “at some point in the last quarter century, Klein lost his goddamn mind,” and that “he just makes shit up, and it’s not even good.” She cannot prove anything in the book is made up, of course — she simply chooses to believe that it is.

Klein has been a journalist for nearly six decades—seven of those years as foreign editor of Newsweek, ten years as the editor in chief of the New York Times Magazine (during which time the magazine won the first Pulitzer Prize in its history), and twenty-seven years as a contributing editor of Vanity Fair. Hence the nastiness with which his books about the Clintons, including the latest, are greeted by the media: he is an apostate of journalism’s left-wing political faith, and must be punished.

The media that otherwise applauds the fanciful behind-the-scenes drama in supposed tell-all books like Game Change, which ridiculed Sarah Palin and was turned into an HBO movie in time for the 2012 elections, dismisses Klein’s reporting on Hillary Clinton.

But Klein’s books about Hillary have featured exclusive interviews and news-breaking stories that other journalists have found hard to match. In many cases, these interviews and stories have proven to be illuminating — and often prescient.

In The Truth About Hillary (2005), Klein was the first journalist to prove that Hillary knew about Bill Clinton’s affair with Monica Lewinsky long before it became public, and that when the story broke she tried to pretend she was shocked. He also documented the original source of Hillary’s radical politics, the Reverend Don Jones, Hillary’s youth minister, who gave Hillary a subscription to motive, a leftwing publication that favored Cuba, socialism, and the Black Panthers. She would go on to write her senior thesis at Wellesley about radical community organizer Saul Alinsky, corresponding with Alinsky himself.

In The Amateur (2012), Klein unmasked Valerie Jarrett’s shadow presidency and her infighting with Obama’s first chief of staff, Rahm Emanuel. He also revealed Obama’s rift with Oprah Winfrey, who declined to campaign for Obama in 2012. The book came out in May; the New York Daily News reported on September 3 — nearly three months later — that Oprah would skip the Democratic National Convention. Later, in August, Klein reported that Obama offered the 2012 vice presidential spot to Clinton, a story that was confirmed a year later by Mark Halperin and John Heilemann in their book Double Down.

In Blood Feud (2014), Klein was the first journalist to report on the jealousy and antipathy that divide the Obamas and the Clintons. The hatred between the Clintons and Obamas was substantiated two years later, on September 16, 2016, when Colin Powell’s emails were leaked to the public. Klein also reported, correctly, that Hillary knew from the beginning that the attack on the U.S. consulate in Benghazi was carried out by an affiliate of al Qaeda. And he was the first journalist to uncover the true story of Hillary’s fainting spell and concussion while she was secretary of state, anticipating new doubts about her health.

Nuzzi calls Klein’s books “narrative fiction,” which better describes Hillary Clinton’s stories about herself. Clinton’s more egregious biographical whoppers — the Tuzla dash, for example — are largely buried and forgotten, while the media spends months lending undue credibility to her lies about a YouTube video in Benghazi, or about never sending classified material on her private email server, before finally admitting the truth and then promptly ignoring it, once she is past the worst danger.

Klein relies heavily on unnamed sources, and dialogue that is reconstructed second- or even third-hand. That is fair game for criticism, as is his writing style, which tends toward the dramatic. And every journalist is bound to make a mistake or two.

But many journalists, including Halperin and Heinemann of Game Change renown, use information from anonymous sources to tell important stories that otherwise would go unreported. Why are their stories about Sarah Palin widely believed, while Klein’s stories about Hillary Clinton are treated as toxic until proven true?

The answer is too obvious to require explanation.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. His new book, See No Evil: 19 Hard Truths the Left Can’t Handle, is available from Regnery through Amazon. Follow him on Twitter at @joelpollak.