Mrs. Clinton’s speech was intended to link Mr. Trump to a fringe ideology of conspiracies and hate, but for the leaders of the alt-right, the attention from the Democratic presidential nominee was a moment in the political spotlight that offered a new level of credibility. It also provided a valuable opportunity for fund-raising and recruiting.
Jared Taylor, editor of the white nationalist publication American Renaissance, live-tweeted Mrs. Clinton’s remarks, questioning her praise of establishment Republicans and eagerly anticipating her discussion of his community.
“Come on, Hillary,” he wrote. “Talk about Alt Right.”
In an ode to Mr. Trump’s characterization of Jeb Bush, Mr. Taylor described her speech as “low energy.”
Other white nationalists mocked Mrs. Clinton, saying she sounded like a neoconservative and a “grandma,” while welcoming the publicity.
Mr. Trump has publicly kept his distance from the alt-right, but his critics have accused him of offering subtle cues to invite its support. His appointment of Stephen K. Bannon, the head of Breitbart News, to be chief executive of his campaign was cheered by alt-right members who are avid readers of the Breitbart website.
The alt-right claims to support the preservation of white culture in the United States, and many of its members want to see an overhaul of the entire political system. However, its views are widely seen as white supremacist and anti-Semitic.
Many who align themselves with alt-right philosophies say that they do not subscribe to all of Mr. Trump’s policies, but that electing him would be a step in the right direction because of his “America First” worldviewand his hard line on immigration. This week, some expressed disappointment that Mr. Trump appeared to be softening his tone on deporting people who are in the country illegally.
Richard B. Spencer, the president of the white-nationalist National Policy Institute, who is credited with coming up with the name “alt-right,” pushed back against claims that the group promotes violence and said in a statement that there was a double standard at play.
“While Hillary & Co. condemn the alt-right — nonviolent activists seeking social change, largely through a vibrant internet presence — she allows noted supporters of terror to attend her rallies and has never once disavowed the actions of domestic terrorists associated with Black Lives Matter,” Mr. Spencer said.
Mrs. Clinton’s public criticism of the alt-right could turn out to be a boon for the movement, and its members did their best to capitalize on the moment.
Some, in an effort to show a lighthearted side, circulated footage of Mr. Taylor playing the saxophone at the group’s most recent conference. The white nationalist website VDare published a “What Is the Alt-Right?” video and blasted out a fund-raising pitch warning, “Hillary wants to ignite a witch hunt against the alt-right because she knows we are finally starting to make an impact on the public’s thinking about immigration.” And the Stormfront forum set up an online thread for potential new members.
After Mrs. Clinton’s speech, one group of white nationalists convened a 90-minute videoconference that was broadcast on YouTube. The consensus was that Mrs. Clinton was “toothless” and “lackluster,” and they expressed disappointment that she had not mentioned alt-right leaders by name. She made reference only to David Duke, the former Klansman whose support Mr. Trump was slow to disavow.
Although the alt-right tried to put its best foot forward, there was plenty of venom directed at Mrs. Clinton, and the conspiracy theories ran wild. A popular attack was the continuing effort to raise questions about her health. By addressing the alt-right in such a prominent setting, Mrs. Clinton ran the risk of helping its cause. But Richard Cohen, the president of the Southern Poverty Law Center, which tracks hate groups, dismissed the idea that Mrs. Clinton was doing the public a disservice by drawing attention to the alt-right.
“I think every public official ought to denounce racism, and that is what Secretary Clinton did,” Mr. Cohen said, noting that the alt-right ideology opposes the notion that all people are equal.
Referring to the term “alt-right,” which was trending on Twitter, he added, “It is a fancy, almost antiseptic term for white supremacy in the digital world.