Brock started his career in 1986 writing for the conservative magazine Insight, a sister publication of the Washington Times. In March 1992, Brock published a sharply critical story about Clarence Thomas accuser Anita Hill in American Spectator, in which he described her as "a little bit nutty and a little bit slutty." A little over a year later, in April 1993, Brock published a book titled The Real Anita Hill.
In the January 1994 issue of American Spectator, Brock, by then on staff at the magazine, published a story about Bill Clinton that made accusations that became Troopergate. Among other things, the story contained the first printed reference to Paula Jones, referring to a woman named Paula who offered to be Clinton's girlfriend. Jones called Brock's account of her encounter with Clinton "totally wrong." The story received an award later that year from the Western Journalism Center.
Three years later, Brock surprised conservatives by publishing a sympathetic biography of Hillary Clinton. In July 1997, Brock published a confessional piece in Esquire magazine titled "I Was a Conservative Hit Man," in which he recanted much of what he said in his two best-known Spectator articles. Discouraged at the reaction his Hillary Clinton biography received, he said, "I... want out. David Brock the Road Warrior of the Right is dead." Four months later, American Spectator fired him.
Writing again for Esquire in April 1998, Brock apologized to Clinton for his contributions to Troopergate, calling it simply part of an anti-Clinton crusade. He elaborated further on his recantations in his 2001 book, Blinded by the Right: The Conscience of an Ex-Conservative.