Democratic presidential nominee Hillary Clinton said the conservative movement known as the "alt-right" was an "emerging racist ideology." (Victoria Walker/The Washington Post)

A series of racially charged accusations dominated the presidential campaign Thursday, with Democrat Hillary Clinton accusing Donald Trump of “taking hate groups mainstream,” while the Republican nominee repeatedly claimed that Clinton is a “bigot” toward African Americans.

Clinton started the day by releasing a video that featured Ku Klux Klan members and white supremacists touting Trump’s candidacy — then gave an afternoon speech condemning Trump’s racially inflammatory remarks and support within the “alt-right,” which she described as an “emerging racist ideology.”

“Trump is reinforcing harmful stereotypes and offering a dog whistle to his most hateful supporters,” she said in the speech in Reno. “It’s a disturbing preview of what kind of president he’d be.”

Trump, meanwhile, declared in an interview on CNN that Clinton is a bigot — an accusation that he first made at a rally in Mississippi Wednesday night, but that he repeated several times under questioning from CNN’s Anderson Cooper.

“She is a bigot,” Trump said in the interview, which was broadcast Thursday. “If you look at what’s happening to the inner cities, you look at what’s happening to African Americans and Hispanics in this country, where she talks all the time.”

Speaking at a rally in New Hampshire on Aug. 25, Republican presidential candidate Donald Trump warned supporters that Democratic rival Hillary Clinton will accuse them of racism, saying that is a tired strategy of the Democratic party. (The Washington Post)

The blisteringly direct accusations brought the subjects of race and bigotry, previously undercurrents, to the surface of this year’s presidential election. And the exchanges hinted at just how nasty the verbal battle between Clinton and Trump could become in the roughly 10 weeks until the general election.

Clinton’s aim is to diminish Trump in the eyes of Americans uncomfortable voting for someone who appeals to racists, perhaps even winning over some moderate Republicans. Trump is fighting that image by appealing to minority voters while questioning Clinton’s record on race issues, noting that Democrats have long controlled cities where many African Americans continue to live in poverty.

While Clinton stopped short of accusing Trump directly of being a racist, Trump offered no such restraint with his remarks.

Clinton’s speech Thursday afternoon, delivered at a community college in this general-election battleground state, focused particularly on Trump’s connection to the alt-right.

It’s a movement that predates Trump, but it was his presidential campaign that brought it into the mainstream. From the moment he told a national audience that Mexico was sending rapists and drug dealers across the border, Trump surged in the polls.

The movement has come under new scrutiny in the wake of a leadership shake-up in the Trump campaign that included the installation of Breitbart News head Steve Bannon as the campaign’s chief executive. Bannon has described Breitbart News as “the platform for the alt-right.”

“The de facto merger between Breitbart and the Trump Campaign represents a landmark achievement for the ‘alt-right,’ ” Clinton said. “A fringe element has effectively taken over the Republican Party.”

She ticked off several recent headlines from the site in an effort to discredit Bannon. Among them: “Hoist It High And Proud: The Confederate Flag Proclaims a Glorious Heritage.” That appeared, Clinton said, shortly after the mass shooting in a Charleston, S.C., church.

Clinton also called Trump “a man with a long history of racial discrimination, who traffics in dark conspiracy theories drawn from the pages of supermarket tabloids and the far dark reaches of the Internet.”

In his own speech in New Hampshire earlier Thursday, Trump tried to discredit Clinton’s argument before she had made it, calling it “one of the most brazen attempts at distraction in the history of politics” and an attempt to spread “smears and her lies about decent people.”

“It’s the oldest play in the Democratic playbook,” he said. “When Democratic policies fail, they are left with only this one tired argument: You’re racist, you’re racist, you’re racist. They keep saying it: You’re racist. It’s a tired, disgusting argument and it’s so totally predictable.”

Trump framed Clinton’s speech not as an attack on him but as an attack on the “millions of decent Americans” who support him. He provided a point-by-point defense of some of his most controversial stances — including blocking refugees from entering the country, cracking down on illegal immigration and intensifying policing — saying that it is not racist, Islamophobic or hard-hearted to want to keep Americans safe.

“To Hillary Clinton and her donors and advisers pushing her to spread smears and her lies about decent people, I have three words, I want you to remember these three words: Shame. On. You,” Trump said.

The fact that questions about race and bigotry dominated the day was by itself a victory for Clinton. She and her top aides have spent several days trying to fend off new questions about foreign donations to the Clinton Foundation and her use of a private email server during her tenure as secretary of state.

In a contest in which both Clinton and Trump are viewed unfavorably by wide swaths of the electorate, both are seeking to make the race a referendum on the fitness of the other. Clinton’s speech here was an attempt to put the spotlight back on Trump on an issue her camp hopes will continue to be a hot topic through November, although Trump made a clear play to try to neutralize that by questioning her own attitudes toward black Americans.

In her speech, Clinton chided Trump for having questioned the citizenship of President Obama, the first African American to hold the position; for having been sued by the Justice Department for alleged discrimination in rental housing; for questioning the impartiality of a judge of Mexican heritage; and for proposing to use deportation forces to remove 11 million undocumented immigrants from the country — an idea Trump now seems to be wavering on.

In recent days, Trump has been aggressively trying to shed the label of racist, which his campaign and supporters say is unfair and unmerited. He has increased the number of minority surrogates speaking on his behalf on cable news and at his rallies, and he is planning to take trips into urban areas soon to visit churches, charter schools and small businesses in black and Latino communities.

The purpose of this pitch is not only to reach out to minority voters but also to soften Trump’s image among white moderates, notably women, who have been taken aback by Trump’s rhetoric. He has delivered the vast majority of his speeches to overwhelmingly white crowds, even when he appears in cities with large minority populations.

“Hillary Clinton is a bigot who sees people of color only as votes, not as human beings worthy of a better future,” Trump said at the rally Wednesday night in Mississippi. “She’s going to do nothing for African Americans. She’s going to do nothing for the Hispanics.”

The line was included in prepared remarks distributed to reporters, and it seemed to catch many in the white crowd by surprise, triggering a delayed and somewhat brief round of cheers and applause. A woman standing behind Trump grimaced at the comment, her eyes widening as she seemed unsure whether she should clap. Another woman seated in the upper tier of the arena approvingly shouted, “Yeah! Yeah!”

Trump has accused Clinton of bigotry before, but those comments did not land with the same impact.

In an interview on Thursday, CNN’s Anderson Cooper grilled Trump on his use of the insult.

“But how is she bigoted?” ­Cooper said at one point. “Bigotry is having hatred towards a particular group.”

“Because she is selling them down the tubes because she’s not doing anything for those communities,” Trump responded. “She talks a good game. But she doesn’t do anything.”

Cooper pressed again: “So you’re saying she has hatred or dislike of black people?”

“Her policies are bigoted because she knows they’re not going to work,” Trump responded.

“But you’re saying she’s personally bigoted . . .” Cooper said.

“Oh, she is. Of course she is,” Trump said. “Her policies. They’re her policies she comes out with the policies and others that believe like she does also but she came out with policies over the years. . . . This is over the years. Long time. She’s totally bigoted, there’s no question about that.”

Trump’s blunt pitch to minorities has been criticized by some for casting all blacks and Hispanics as impoverished, undereducated and underemployed.

“What do you have to lose?” Trump said at a rally in Tampa on Wednesday afternoon. “It cannot get any worse. And believe me, I’m going to fix it. . . . I’ll be able to make sure that when you walk down the street in your inner city or wherever you are, you’re not going to be shot. Your child isn’t going to be shot.”

Trump’s ongoing efforts to soften his image also carry some risk with his more fervent supporters.

Conservative activist and author Ann Coulter has been taking Trump to task on Twitter and talk shows in recent days as Trump has signaled that he might back off his plan to remove all the roughly 11 million immigrants currently in the country illegally.

Although Trump has yet to clearly state what he now believes, he has made a series of comments that seem to echo the immigration reform stances of several of his former Republican rivals whom he once mocked for being “weak” on illegal immigration.

Nevada, the site of Clinton’s speech Thursday and home to a burgeoning Latino population, is one state watching the immigration debate closely.

President Obama carried the state against Mitt Romney in 2012, but recent polls here have showed Clinton with no more than a modest lead over Trump.

David Weigel contributed to this report.