In 2004, he founded Media Matters for America, a non-profit organization which describes itself as a "progressive research and information center dedicated to comprehensively monitoring, analyzing and correcting conservative misinformation in the U.S.
"[18] In a January 1994 The American Spectator story about Bill Clinton's time as governor of Arkansas, Brock, by then on staff at the magazine, made accusations that bred Troopergate.
After the success of The Real Anita Hill, Simon & Schuster's then-conservative-focused Free Press subsidiary paid Brock a large advance to write a book about Hillary Clinton.
In Blinded by the Right (2002), Brock said that he had reached a turning point: he had thoroughly examined charges against the Clintons, could not find any evidence of wrongdoing, and did not want to make any more misleading claims.
John Balzar, reviewing the book in the Los Angeles Times, called it "[e]xhaustive to the point of exhaustion" and "predictably critical but unexpectedly measured, at least in comparison to what Beltway gossips anticipated".
[5] In July 1997, Esquire magazine published a confessional piece by Brock entitled "Confessions of a Right-Wing Hit Man" in which he recanted much of what he said in his two best-known American Spectator articles and criticized his own reporting methods.
In this book, an "outgrowth" of Confessions of a Right-Wing Hit Man, Brock charted what the Daily Beast called his "remarkable metamorphosis to ardent acolyte from sworn enemy of Bill and Hillary Clinton.
He wrote that he had been "a mad dog, an emotional monster", "a whore for the cash", "a Jew in Hitler's army", and "a witting cog in the Republican sleaze machine", and asserted that he hadn't known "what good reporting was".
Hitchens was particularly harsh, stating that Brock "inserts a completely gratuitous slander against a decent woman, all of whose independent assertions have survived meticulous fact-checking".
Later, according to Politico, "Brock was invited to the former president's Harlem office where he was shocked to discover Clinton had purchased dozens of copies — and stuffed them into a big cabinet".
Publishers Weekly (PW) described it as a "blistering j'accuse" that, compared to Blinded by the Right, was "a less gossipy and more systematic assault on the right-wing media juggernaut."
According to PW, Brock depicted the mainstream media as being "cowed by spurious charges of 'liberal bias'" and as therefore having "abandoned their role as objective arbiters of truth in favor of an uncritical airing of partisan ideology in the name of 'balance.'"
"[4] In 2014, The Nation stated that "Brock, in partnership with fundraiser Mary Pat Bonner—often described as his secret weapon—has turned out to be unparalleled at maintaining rich liberals' loyalty and support."
[6] The Nation has described American Bridge as "the natural next step" after MMA, explaining that "Brock took the Media Matters method—which involves monitoring virtually every word uttered by the right-wing media—and transferred it to the realm of Republican politicians.
"[6] Democratic operative Paul Begala told The Nation that in 2012 American Bridge "produced for us a 950-page book of every business deal of Mitt Romney's career.
"[6] In late 2013 Brock founded Correct the Record, described by The New York Times as Hillary Clinton's "own personal media watchdog", keeping track of all negative news surrounding her.
"[45] In September 2015, Brock and Correct the Record produced a piece on Bernie Sanders, linking him to Hugo Chávez and British Labour Party leader Jeremy Corbyn.
[4] In early 2014, Brock was named to the board of Priorities USA Action as the super PAC also announced its support for a possible Hillary Clinton presidential run in 2016.
The New York Times had run an article questioning his groups' fundraising practices, and he charged that "current and former Priorities officials were behind this specious and malicious attack on the integrity of these critical organizations.
Politico described this as "a major power play that aligns liberal muscle more fully behind the Democratic Party — and Hillary Clinton" and said that Brock had set forth a plan "to turn the group into a more muscular — and likely partisan — attack dog.
"[52] While CREW operates as a 501(c)3 nonprofit prohibited from engaging in partisan activity, Brock made clear he intends to create a more politically oriented arm registered under section 501(c)4, and also form a new overtly partisan watchdog group called The American Democracy Legal Fund registered under section 527, allowing it to engage in direct political activity.
When asked if CREW would still continue pursuing complaints against Democrats, Brock responded, "No party has a monopoly on corruption and at this early juncture, we are not making categorical statements about anything that we will and won't do.
[5] Calling the book a "trenchant j'accuse", Publishers Weekly said that parts of it "read like a fund-raising prospectus" for MMA but concluded that while "Brock's rhetorical venom and naked partisanship will alienate some readers ... his sharp-eyed reporting makes for a spirited challenge to business-as-usual political discourse.
[24] It was reported on September 1, 2015, that a batch of Hillary Clinton's emails that had been made public included one from Brock entitled "Memo on Impeaching Clarence Thomas".
[57] Politico reported in January 2016 that Brock was preparing a new advertisement that would call on presidential candidate Bernie Sanders "to release his medical records before the Iowa caucuses on Feb.
Briggs added: "Twenty-five years ago it was Brock – a mud-slinging, right-wing extremist – who tried to destroy Anita Hill, a distinguished African American law professor.
"[59] At a campaign event in Iowa in late January 2016, Bernie Sanders denied any plans to "bus in out-of-state college students to caucus for him", charging that this was a lie and attributing it to Brock.
"[61] The New York Times reported in December 2017 that a group founded by Brock had spent $200,000 in an unsuccessful effort to bring forward accusations of sexual misconduct against Donald Trump during the 2016 presidential race.
"[20] Similarly, The Guardian referred in 2014 to "residual unease among some liberal operatives that Brock's conversion story fits into a pattern of opportunism and self-promotion rather than ideological transformation.
[70][71] Uygur said that Brock's January 10, 2017, open letter of apology to Sanders and his voters,[72] was disingenuous because it was motivated by a desire to raise money from wealthy Democratic donors and to foster a perception of himself as being a member of the U.S. progressive movement.