On Thursday afternoon, speaking to an audience in Reno, Nevada, Hillary Clinton took a knife to Donald Trump’s campaign.

The subject of her speech was a movement called the “alt-right.” To the vast majority of Americans, this means nothing. And that “vast majority” includes most of the audience for the 2016 presidential election. If you watch broadcast and cable news, if you read newspapers and magazines, if you listen to political radio and podcasts, there’s a strong chance you haven’t heard the term either. But if you experience politics through social media—and Twitter in particular—the alt-right is an all-too-familiar phenomenon.

Broadly, the alt-right is a loose collection of bloggers, activists, intellectuals, and media figures. It’s conservative but unconcerned with the usual right-wing platform of low spending, low taxes, and small government. Instead, the alt-right is preoccupied with the status of white America, which it sees as under siege from Hispanic immigration, diversity, and “political correctness.” The alt-right has its origins in the white nationalists and “white identity” movements of the 1990s, but in the past year, it has found a home on Twitter and other social media, where adherents traffic in white supremacist and anti-Semitic memes; threaten and harass female, nonwhite, and Jewish users; and decry “white genocide,” defined as multiculturalism. These users see themselves as an intellectual and political vanguard defending European civilization from the brown hordes. In reality, they’re white supremacists with a knack for branding.

If these white supremacists are relevant, it’s because of Donald Trump. In ways small and large, the Republican nominee for president has legitimized their presence in public life, from retweeting alt-right Twitter accounts and sharing anti-Semitic memes to his followers, to hiring the executive chairman of Breitbart (an online haven for the movement), to courting figures such as Nigel Farage, the Brexit tubthumper who stirs up similar sentiments of racism and xenophobia. Trump is their avatar, and he welcomes their attention.

The upside, for Trump, is that it gives him a fervent base of supporters who evangelize on his behalf in every medium they can access. The downside is that it makes Trump toxic to vast groups of Americans. Fifty-nine percent of voters, according to a new poll from Quinnipiac University, say that “the way Donald Trump talks appeals to bigotry.” Likewise, in polling by the Trump campaign, large numbers describe the real estate mogul as “unqualified” and “racist.” These numbers are why Trump has lost white voters with degrees—the first Republican to do so since the advent of modern polling—and why he struggles with white women in particular.

All of which is why, for the past week, Trump has tried to soften his approach, with an attempt at performing empathy for black voters and a newly muddled stance on immigration, meant to appeal to hardliners and moderates. If it works, if Trump can show those white voters that he’s not as rigid and prejudiced as he might seem, then he could make gains. He could even have a shot at the White House.

Clinton’s address on Thursday had one goal: to tie Trump to the alt-right by reminding voters of his statements and associations, going back to the beginning of his campaign. And she did just that. “We all remember when Trump said a distinguished federal judge born in Indiana couldn’t be trusted to do his job because, quote, ‘He’s a Mexican,’ ” said Clinton, reminding her audience of Trump’s attacks on Gonzalo Curiel, the judge presiding over the lawsuit against Trump University. “His campaign famously posted an anti-Semitic image—a Star of David imposed over a sea of dollar bills—that first appeared on a white supremacist website,” she went on, pointing back to an example from earlier in the summer. She kept on, citing incident after incident in which Trump indulged in bigotry and hatred, from his claim that American Muslims cheered the 9/11 attacks to his long-standing birtherism.

Her most important move in the speech was to contrast Trump’s behavior with that of past Republican presidents and nominees. Clinton favorably cited Bob Dole’s admonition against racists during the 1996 Republican National Convention, praised George W. Bush for his outreach to Muslim Americans after 9/11, and highlighted John McCain for his pushback against racist conspiracy theories during the 2008 presidential election.

As analysis, Clinton’s argument about Trump’s distance from the rest of the GOP is wrong. At various points in their campaigns, those Republicans gave their winks and nods to the most toxic elements in their party. And broadly, the Republican Party has long appealed to the white racial resentment and hostility that now fuels the Trump campaign in explicit form.

As strategy, however, Clinton’s approach is shrewd. She could tie the entire GOP to Trump, but at the risk of embattling Republican voters and activating a tribal loyalty to the party. By distancing Trump from the Republican mainstream, she offers those voters another choice: You can vote for me, or if that’s too much, you can just not vote at all. Either way, Trump’s margin shrinks. And if those voters decide to abandon the polls in November, it could bolster Democrats even further as they try to take the House and Senate back from the Republican Party.

In the meantime, by highlighting Trump’s prejudiced rhetoric and his close ties to white supremacists, Clinton disrupts his attempted pivot, forcing him to litigate these questions and even provoking him and his allies into reinforcing her argument.

Neither Clinton nor her campaign brought much fanfare to this address. The speech was short, the audience was small, and the proceedings were a bit more sedate than the usual political rally. But that’s because this wasn’t a usual speech, a fact underscored by Clinton’s delivery, which was calm—almost conversational. In the years since the Civil Rights Act of 1964, it has not been normal for a major party nominee, such as Donald Trump, to have open ties to white nationalists and conspiracy theorists. It has not been normal for that nominee to push religious discrimination as a matter of public policy. It has not been normal for him to attack federal officials on the basis of their heritage.

That Clinton gave this speech at all is another stark reminder that this election is not normal and that the stakes—the potential elevation of outright white supremacists in government and society—are incredibly high. And if there’s a question to take away from Thursday, it’s this one: Why couldn’t Republican leaders say this when they had the chance?

Read more Slate coverage of the 2016 campaign.