WASHINGTON — Hillary Clinton launched into a new, aggressive line of attack against Donald Trump on Thursday, accusing him of helping foment racial hatred and refashioning the Republican Party as a welcome home for white nationalists.

“He is taking hate groups mainstream and helping a radical fringe take over the Republican Party,” Clinton said. “His disregard for the values that make our country great is profoundly dangerous.”

In a presidential race that already stood out for its relentless volleys of personal insults and accusations, Clinton’s allegations that Trump is warmly welcoming Ku Klux Klan sympathizers, neo-Nazis and other fringe racist elements into GOP politics stands out.

Trump didn’t wait for Clinton to deliver her highly anticipated speech to respond, using his own appearance earlier in the day in Manchester, N.H., to call her remarks a “disgusting” effort to deflect attention from her own controversies. But he avoided criticizing the elements Clinton associated him with. Trump said that Republicans who had responded in such a way in the past were weak apologists.

Clinton took aim at Trump’s affiliations with the so-called alt-right movement, a loosely organized network of anti-establishment activists on the right that helped fuel the GOP nominee’s rise. The largely online movement includes legions of openly racist and anti-Semitic activists who operate in what Clinton described as the “far dark reaches of the internet.”

The alt-right has long cheered Trump, but their ties were strengthened in his latest campaign shake-up. Stephen K. Bannon, former editor of the alt-right favorite Breitbart News, now runs Trump’s campaign.

“There’s always been a paranoid fringe in our politics, a lot of it arising from racial resentment,” Clinton said. “But it’s never had the nominee of a major party stoking it, encouraging it, and giving it a national megaphone until now.”

Clinton called out Trump for retweeting white supremacists, for posting an online attack on her that was widely perceived as anti-Semitic — it included a Star of David over piles of dollar bills — and for initially selecting a white nationalist leader as a convention delegate from California.

“When Trump was asked about anti-Semitic slurs and death threats coming from his supporters, he refused to condemn them,” Clinton said. “Through it all, he has continued pushing discredited conspiracy theories with racist undertones.”

During his own speech just before, Trump accused Clinton of making a desperation play as controversies continue to swirl around her involving her private email server and questions of whether big donors to the Clinton Foundation got special access to her when she was secretary of State.

“It’s the oldest play in the Democratic playbook,” Trump said. “When Democratic policies fail, they are left with only this one tired argument: ‘You’re racist, you’re racist, you’re racist.’ … Hillary Clinton isn’t just attacking me. She is attacking all of the decent people of all backgrounds who support this incredible, once-in-a-lifetime movement.”

No recent major presidential nominee has been as adored by white nationalists and anti-Semites as Trump. They are encouraged by his vows to deport millions of people in the U.S. illegally, build a giant wall on the U.S.-Mexico border, and ban Muslims from entering the U.S.

It’s not the first time a presidential candidate has been in the uncomfortable position of having fringe racists cheer them on, but others have tended to be more aggressive about immediately distancing themselves from such supporters.

In 2008, Sen. John McCain, R-Ariz., pushed back against a voter at a town hall who launched into a rant about then-Sen. Barack Obama supposedly being a Muslim; Obama is Christian. Clinton remarked in her speech about how former President George W. Bush led the call for religious tolerance after the Sept. 11, 2001, terrorist attacks, when anti-Islamic sentiment was heightened in the U.S.

Trump has been more cautious about disavowing support from white nationalists. When asked in February by CNN about his endorsement from former Ku Klux Klan leader David Duke of Louisiana, Trump first said he knew nothing about Duke. After the moderator explained he was a former Klan leader, Trump said: “Honestly, I don’t know David Duke. I don’t believe I have ever met him. I’m pretty sure I didn’t meet him. And I just don’t know anything about him.”

The Clinton campaign included footage of such wavering in a new video that included white supremacists offering praise for the GOP nominee. It closed with a warning in bold text: “If Trump wins, they could be running the country.”

In Nevada, where Clinton delivered her address Thursday, she and Trump are locked in a close race. Her success there depends largely on whether she can turn out a large share of Latino voters, and the speech sought to motivate them by linking Trump’s mass deportation plan and calls to build a border wall to white nationalists.

Trump is making his own, very different appeal to minorities. In New Hampshire, he continued his “What the hell have you got to lose?” appeal to blacks, during which he proposes they take a chance on him if for no other reason than his dim assessment of the conditions they live under in America’s Democratic-controlled cities.

“It can’t get any worse than it is right now,” he said.

He charged Democrats with confining blacks to a dismal existence of horrendous schools and unsafe neighborhoods, and said he could pull them out of it. The pitch, which he continues to make before mostly white audiences, has been met with little enthusiasm by nonwhite voters.

Clinton said Trump’s message was offensive.

“Trump has stood up in front of largely white audiences and described black communities in such insulting and ignorant terms,” Clinton said. “It really does take a lot of nerve to ask people he’s ignored and mistreated for decades, ‘What do you have to lose?’ because the answer is everything.”