At a vigil for the shooting victims, Mr. DeSantis had to speak over loud boos from a largely Black crowd. His agenda in Florida has earned him few Black allies.Days after being sworn in as Florida’s governor in 2019, Ron DeSantis pardoned the Groveland Four, a group of Black men who had been wrongfully accused of sexually assaulting a white woman decades earlier.At the time, Mr. DeSantis’s decision seemed like it could serve as a vital olive branch to Florida’s wary African American community. Accusations of racism had trailed him throughout a bruising general election, which he had begun by warning voters not to “monkey this up” by voting for his Democratic opponent, who was Black. The case of the Groveland Four, who all died before having their names cleared, had received national attention, and Mr. DeSantis said their treatment represented a “miscarriage of justice.”Four years later, Mr. DeSantis’s relationship with Black Floridians could hardly be worse. As he moved increasingly to the right ahead of his run for president, Mr. DeSantis pushed an agenda that cemented his status as a rising conservative star nationally but that has outraged many Black voters and leaders in his home state.Those policies include changing how slavery is taught in schools, cutting funding for diversity and inclusion initiatives and redistricting a Black-led congressional district in northern Florida out of existence. Some Black professional groups have stopped holding conferences in the state, while several Black leaders have condemned Florida — and Mr. DeSantis — as an example of racism in policymaking.Now, a racially motivated shooting in Jacksonville that killed three Black people over the weekend has escalated those tensions to new heights.At a vigil on Sunday for the victims, Mr. DeSantis had to speak over loud boos from the largely Black crowd. He condemned the murders and called the killer, a white man who the authorities said intentionally targeted Black people before killing himself, “a major-league scumbag.”Mr. DeSantis was confronted with loud boos at the vigil for the shooting victims.John Raoux/Associated PressJeffrey Rumlin, a pastor who spoke after Mr. DeSantis, offered a correction. “Respect for the governor,” Mr. Rumlin, who is Black, told the crowd, but “he was not a scumbag. He was a racist.”Shevrin Jones, a state senator from South Florida, said Mr. DeSantis’s reception at the vigil was telling.“The response from Jacksonville’s Black community was the response from the Black community across the state of Florida,” said Mr. Jones, a Black Democrat. “We’ve never had a relationship with the governor.”Mr. DeSantis’s office, which is preparing for a major hurricane, did not respond to a request for comment. Neither did his campaign.Kiyan Michael, a Republican state representative from the Jacksonville area, defended Mr. DeSantis. Far from being racist, she said, his support for policies like universal school choice and efforts to crack down on the employment of undocumented immigrants, had helped African Americans. The governor made modest gains with Black voters in his re-election last year, according to an Associated Press analysis.Ms. Michael, who is Black, also praised Mr. DeSantis for attending the Jacksonville vigil.“He could have sent somebody in his place. He didn’t,” she said. “He knew that he was going into a hornet’s nest, but he came himself to show his heart, his concern, his compassion.”The list of policies that Mr. DeSantis’s critics describe as harmful to African Americans is long, and many have been challenged in court.As governor, Mr. DeSantis sought to restrict enacting a popular referendum to restore the voting rights of many felons. After the George Floyd rallies, he signed legislation that many civil rights activists said criminalized political protests, as well as laws eliminating diversity and inclusion spending from state universities and restricting the teaching of the academic framework known as critical race theory. He also set up a new state police force to enforce election laws that arrested mainly Black people in a high-profile sweep and has seen many of its cases stumble in court. And he removed two elected state attorneys from office. Both were Democrats who supported criminal justice reform. One was Black.Perhaps the biggest backlash was early this year, when Florida education officials rejected an Advanced Placement course on African American studies and subsequently adopted new standards that said students should be taught how enslaved people “developed skills which, in some instances, could be applied for their personal benefit.” The line was widely denounced, with a number of Black conservatives, including Mr. DeSantis’s 2024 rival Senator Tim Scott of South Carolina, criticizing its inclusion.In the presidential race, Mr. DeSantis has leaned on his “war on woke,” aiming to eliminate liberal viewpoints on race and gender from many parts of public life.Daniel A. Varela/Miami Herald, via Associated PressA backlash came when Florida education officials said students should be taught how enslaved people “developed skills which, in some instances, could be applied for their personal benefit.”Alicia Devine/Tallahassee Democrat, via Associated PressMr. DeSantis defended the changes, saying on Fox News this month that the standards overwhelmingly showed the “injustices of slavery,” while also demonstrating that “people acquired skills in spite of slavery, not because of it, and then they used those when they achieved their freedom.”As a young man, Mr. DeSantis taught American history at a private boarding school in Georgia. There, The New York Times previously reported, some students said he offered lessons on the Civil War that seemed slanted, factually wrong and sometimes presented in ways that sounded like attempts to justify slavery.On the campaign trail, Mr. DeSantis has leaned on his record leading Florida, particularly his “war on woke,” which seeks to eliminate liberal viewpoints on race and gender from many parts of public life. Republican primary voters have generally responded well, although Mr. DeSantis is still polling far behind the front-runner, former President Donald J. Trump.A general election, however, could be a different story. Mr. DeSantis’s status as a lightning rod for racial issues could galvanize Black turnout against him. Black voters are a key part of the Democratic electorate and their participation at the polls is vital. In 2016, Hillary Clinton lost to Mr. Trump as Black turnout declined in a presidential election for the first time in 20 years, according to the Pew Research Center. Four years later, Joseph R. Biden Jr. won as Black voters came back to the polls in higher numbers.Angie Nixon, a Democratic state representative from Jacksonville, said in an interview that the harms of Mr. DeSantis’s policies were not just limited to Black voters.“He attacks marginalized communities in general because his base doesn’t like them,” Ms. Nixon said. “Because that’s low-hanging fruit for him to gain even more points politically among a base of voters. That’s all he’s ever done — is to try to appeal to a base of people.”Black leaders in Florida described their relationship with Mr. DeSantis as strained at best. In his five years as governor, Mr. DeSantis has held no formal meetings with the state’s legislative Black caucus, according to its members. In contrast, his predecessor, Rick Scott, did sit down with the Black legislators, although the meetings grew contentious and were eventually canceled after the caucus members said they were not being listened to.“I worked with Jeb Bush. I worked with Martinez. I worked with Rick Scott,” said the former congressman Al Lawson, referring to several past Republican Florida governors, including Bob Martinez. “None of them disenfranchised Blacks as much as this governor, DeSantis.”Mr. Lawson’s former district — once heavily Black and Democratic — is now held by a Republican, a product of a redistricting process in which Mr. DeSantis took the unusual step of putting forth his own maps, rather than leaving it entirely to the Legislature, where he enjoys significant support with G.O.P. supermajorities. (A legal challenge asserting that the changes harmed Black voters could restore Mr. Lawson’s district.)This summer, Black national organizations have shunned the state or encouraged their members to travel elsewhere. The National Association of Black Engineers said it would move its 2024 convention, originally set for Orlando, to Atlanta. Alpha Phi Alpha, the nation’s oldest Black fraternity, said it would no longer hold its 2025 convention in Orlando. Both organizations cited recent policies in Florida that they felt posed a threat to Black Americans.In May, the N.A.A.C.P. released a travel advisory to Black Americans considering visiting Florida, calling the state “openly hostile” to members of racial minorities and L.G.B.T.Q. people.Carol Greenlee, 73, pushed for decades for the pardon and eventual exoneration of her father, Charles Greenlee, one of the Groveland Four, over the 1949 crime in Central Florida. She saw the pardon as a moment of hope and reconciliation, especially after the previous governor, Mr. Scott, had declined to take up the case, despite the urging of the Legislature.“It felt like we were moving forward,” she said. “It felt like the pendulum was swinging toward justice.”Ms. Greenlee, who lives in Tennessee but has followed Mr. DeSantis’s path as governor, said his subsequent actions had left her baffled and angry.“I have to shake my head and wonder what happened with some of the stances he has taken,” she said. “It’s almost like a 180-degree turnaround.” More