Former Bush speechwriter Peter Schweizer’s new book, “Clinton Cash,” which alleges that Hillary Clinton used the State Department to do favors for Clinton Foundation donors, is coming under close scrutiny for its unsupported claims and Schweizer’s long history of conservative advocacy.

That advocacy includes an episode in 2010 when Schweizer and his then-colleagues at BigGovernment.com led a racially charged smear campaign against Shirley Sherrod, at the time an official at the U.S. Department of Agriculture.

The smear effort started when BigGovernment.com’s late founder Andrew Breitbart posted a video of Sherrod speaking at an NAACP event, which the site edited to make it appear as though Sherrod admitted to mistreating a white farmer due to racist feelings. Breitbart’s video left out crucial details where Sherrod said that she actually learned that such feelings were wrong and helped the farmer in his struggle. The farmer in question also disputed claims that she acted in a racially prejudicial way. But that didn’t stop conservative media from picking up the video, ultimately leading to the USDA firing Sherrod.

After his video was exposed as deceptive, Breitbart tried to pivot by claiming that he was really more interested in the Pigford case, a civil rights class action suit involving the historical discrimination against black farmers seeking government loans, in which Sherrod was a plaintiff.

Breitbart alleged that Sherrod was really fired as part of a government cover-up of some sort of under-the-table-reparations-vote-buying scheme for African-Americans in which the government was handing out Pigford settlement money to unjustified claimants. His allegation about the real reason for Sherrod’s firing — like the edited video — was without merit, but it gave him a new way to attack Sherrod and the Obama administration at the same time.

In 2011, Schweizer, a BigGovernment.com contributor, appeared on End Times conspiracy theorist Rick Wiles’ “Trunews” program to discuss the allegations, defending Breitbart’s role in the Sherrod affair and repeating discredited talking points about a supposed cover-up and a black-vote-buying scheme championed by Obama.

Schweizer defended Breitbart by saying the conservative media star “didn’t see the original” video of Sherrod’s remarks and “apologized for that,” adding that “the principle was still there, that there was selective justice taking place.” He also agreed with Breitbart’s false claim that the administration only “went after” Sherrod as a result of the Pigford episode: “What we believe happened is that when Sherrod became the public figure as a result of this incident, it gave people a peek at Pigford.”

“Why was there this amazing reaction to this incident? Why was Shirley Sherrod such a hot figure, as it were, that the White House itself intervened and wanted to drop it so quickly? And we believe it was because they did not want attention given to Pigford,” he said. Several months before the interview, the Los Angeles Times reported that USDA emails at the time show that the deceptive video and the resulting conservative media firestorm were the causes of Sherrod’s ousting.

Schweizer also wondered why Obama, then a “senator from Illinois where there are only, as far as we can tell, maybe a handful of black farmers, and of course he comes from an urban background, he’s not a rural senator,” had such a “long and personal interest in Pigford” and wrote letters “to the USDA telling employees to shut up about the fact that they believed there was widespread corruption.”

“It led us to believe and led us to the conclusion that there was a huge political element to Pigford that involved Barack Obama and involved basically buying votes,” he said.

Schweizer told Wiles that then-Sen. Obama tried to “shut up” Pigford whistleblowers: “That’s really because Barack Obama and others see this for their benefit as a way to buy votes. They are passing out $50,000 checks to people who they believe, and I think he’s correct, will ultimately be voting for him. So it’s wealth redistribution, it’s passing the money around to your patrons and it’s sticking taxpayers with a bill that to date is more than $2 billion.”