In the lead-up to and during the Republican National Convention in Cleveland, we’ll be profiling some of the activists and politicians invited to speak at the event. Find more of our Meet the Speakers series here.

The Republican National Convention released a partial list today of the politicians, activists, C-list celebrities and Donald Trump family members who will be speaking at next week’s convention. What the speakers’ list lacks in establishment GOP leaders it makes up for in fringe activists. One name especially stands out: Sheriff David Clarke, the Milwaukee law enforcement officer who has made a name for himself hurling anti-Obama vitriol on Fox News and elsewhere while quietly cozying up to anti-government extremist groups.

Clarke, who is African American, has built a conservative following by enthusiastically bashing President Obama, his Justice Department, Hillary Clinton and the Black Lives Matter movement.

Clarke has called the Black Lives Matter movement “black slime” that “needs to be eradicated from the American society and the American culture,” “garbage” and a “subversive movement” that seeks to overthrow the government, and said that the movement is driven by “an ideology of victimhood with a list of grievances that do not exist.” He has dismissed concerns about police brutality by saying that “black criminal abuse, black criminal brutality” is “the real brutality going on in the United States.” The real problem in “the American ghetto,” he has said, is “modern liberalism.”

Clarke said that Michael Brown, the black teenager shot by police in Ferguson, Missouri, was a “co-conspirator in his own demise” because he “chose thug life.” After Sandra Bland, a black woman who had been thrown to the ground during a traffic stop, died in police custody, Clarke went on Fox News to chastise her. He said that he would have used even more force against a group of black teenagers who were thrown to the ground by police outside a public swimming pool in Ohio, telling people who saw a racial component in the action to “shut up already.”

Clarke has been colorful in his condemnation of President Obama and Hillary Clinton for sympathizing with the Black Lives Matter movement, calling them “straight-up cop haters.” He called Obama a “heartless, soulless bastard” for speaking up about “goons” killed by police and said that the Obama administration’s attempts to address racial disparities in policing were a plot to “emasculate the police” in order to impose dictatorial control.” He accused the president of worsening racial divides in the country by pitting “whites against blacks” and “Hispanics against Americans.”

The sheriff is also happy to throw red meat to his conservative audience on a number of other topics. After the Supreme Court struck down state marriage equality bans, Clarke called for a “revolution” to “get this country back,” complete with “ pitchforks and torches ,” urging his audience to launch a standoff against the federal government the next time a bakery or the like is fined for refusing business to a same-sex couple.

When Trump caused a national uproar when he attacked a judge because of his Mexican-American heritage, Clarke took to his radio show to defend the candidate.

Clarke first became a conservative hero when, in 2013, he aired radio ads in his county urging citizens not to rely on calling 911 but instead to learn to protect themselves against crime. Speaking at the National Rifle Association’s convention last year, he proposed adding a semi-automatic rifle to the Great Seal of the United States. Appearing on conspiracy theorist Alex Jones’ radio program, Clarke warned that a renewal of the federal assault weapons ban would lead to gun confiscations that would spark “the second coming of the American Revolution, the likes of which would make the first revolution pale by comparison.”

While Clarke has no patience for African Americans who have deadly run-ins with the police, he has repeatedly associated himself with anti-government militia groups who have staged armed standoffs with federal government agents or who threaten to defy federal law. Earlier this year, when a group of armed activists took over a federal wildlife refuge in Oregon, Clarke backed their cause, saying that the country had reached a “pitchforks and torches moment” that couldn’t be solved by an election.

In 2013, after he aired his ads discouraging citizens from relying on 911, Clarke accepted the “ Constitutional Sheriff of the Year” award from the Constitutional Sheriffs and Peace Officers Association, an anti-government group that promotes the idea that county sheriffs are the highest law enforcement officers in the country and thus have the power to defy federal laws that they believe are unconstitutional. In his acceptance speech , Clarke declared that “government” was the “common enemy” of the “patriots” in the room. In a radio interview that year, he said that “on an everyday basis, to me, federal government is a bigger threat” than terrorism.

Just this year, Clarke spoke at a fundraising event for the New York chapter of the Oath Keepers, an anti-government group aligned with the Constitutional Sheriffs that urges law enforcement officers and military personnel to defy laws they believe are unconstitutional and encourages its members to form militias ready to defy an out-of-control federal government. At that event, Clarke called Black Lives Matter a “hate group” and vowed to do “everything I can” to get Trump elected president.