Members of white nationalists clash a group of counter-protesters in Charlottesville, Virginia, U.S., August 12, 2017. Joshua Roberts/Reuters

President Donald Trump challenged a reporter to "define the alt-right" on Monday when she asked about a statement released by Sen. John McCain in which he connected the attacks on National Security Adviser H.R. McMaster and the violence in Charlottesville to the white nationalist movement.

Trump told reporters during the press conference that he thinks "there is blame on both sides" for the violence that erupted at a white nationalist rally in Charlottesville, Virginia, on Saturday, doubling down on controversial comments he made in the hours after a 32-year-old counterprotester was run over by an alleged neo-Nazi.

"Sen. McCain said that the alt-right is behind these attacks," the reporter said. "He linked that same group to those that participated in that [car] attack in Charlottesville."

"Define alt-right to me," Trump replied, pointing to the reporter. "You define it. Define it for me. Come on. Let's go."

Trump's challenging tone indicated that he knew how difficult it would be for the reporter to define the "alt-right," an umbrella movement comprising a wide range of far-right viewpoints, on the spot.

Trump's chief strategist, Stephen Bannon, described the "alt-right" in an interview with Mother Jones last year as "nationalist," but not necessarily "white nationalist." He said his company at the time, Breitbart News, was a "platform for the alt-right," while denying that the movement was rooted in racial identity.

But J.M. Berger, an expert on far-right extremism in the United States and a fellow with the International Centre for Counter-Terrorism , said that the community's "center of gravity" has always been white nationalism.

"Not everyone in the alt-right is a overt white nationalist," Berger said in an email. "But white nationalism is definitely the movement's center of gravity, and the term originated with an explicitly white nationalist website."

That website, Alternativeright.com (now Altright.com) marked the birth of the term "alt-right" and was founded by Richard Spencer - the head of the white nationalist think tank the National Policy Institute.

In a September report published by George Washington University comparing the social media efforts of white nationalists with the Islamic State, Berger wrote that neo-Nazi groups began pushing "for more collaboration" among "Nazi-sympathetic and other white nationalist strains" when efforts stalled to recruit more "normal" people.

As of late last year, "Nazi sympathizers represented the largest distinct movement within the white nationalist dataset - about 19% - based on analysis of a random sample of users and the URLs provided in an account's Twitter profile," Berger found.

A white supremacist wears a shirt with the slogan "European Brotherhood" at a rally in Charlottesville, Virginia, U.S., August 12, 2017 Joshua Roberts/Reuters

Spencer and others who identify as "white nationalists" deny that they think white people are superior to other races. But pride in white "culture" and "heritage" and a sense that Jews, black people, and Latinos are trying to "replace" or "cleanse" the white race forms the core of many white nationalists' worldview.

The Associated Press, meanwhile, has determined that the term "alt-right" is "meant as a euphemism to disguise racist aims."

Psychologists Patrick Forscher and Nour Kteily recently conducted a study, which is still in working paper form, of individuals who identify as members of the "alt-right." Forscher and Kteily, a professor at Northwestern University's Kellogg School of Management, found that the subjects had "abundant support" for emphasizing the movement's "perception that certain historically advantaged groups are superior to other groups and need their interests protected."

Many members of the so-called "alt-right" would deny that they are racist. But those studied by Forscher and Kteily reported "high levels of social dominance orientation, strong support for collective action on behalf of white people, and strong opposition to collective action on behalf of black people."

A white nationalist carries the Confederate flag as he walks past counter demonstrators in Charlottesville, Virginia, U.S., August 12, 2017. Joshua Roberts/Reuters

White nationalists, moreover, largely believe that white people should sit atop the west's social hierarchy.

Jason Kessler, the "pro-white" organizer of Saturday's white nationalist rally "Unite the Right," has written that "attacks on Western history and heritage are detrimental to the survival of the tradition which brought us reason, logic, medicine, human rights and took us into outer space."

White supremacist Matthew Heimbach - who said he identifies as a member of the "alt-right" and was invited by Kessler to speak at "Unite the Right" - told Business Insider in an interview late last year that he believes "the organized Jewish community" is heavily involved in "supporting movements that want to destroy nationalism."

In September 2016, Trump's director of strategic communications at the National Security Council, Michael Anton, wrote highly racialized opinion pieces that were signed under the pseudonym "Publius Decius Mus," according to PolitiFact.

"All men are not 'equal in all respects,'" Anton wrote. "They are not 'equal in color, size, intellect, moral developments or social capacity.' People from different nations with different circumstances, histories, beliefs and traditions will - by definition - hold very different conceptions of good government, some irreconcilably opposed to our own."

A crowd of white nationalists, carry an Identity Evropa flag, rally as they are met by a group of counter-protesters in Charlottesville, Virginia, U.S., August 12, 2017. Justin Ide/Reuters

Berger has noted that white nationalists began to organize on social media after President Obama's re-election in 2012 and, importantly, found that they were not just "bored teenagers making trouble" - rather, they were "committed ideologues" who sought to uphold "older strains of organized white nationalism, including neo-Nazism, the Ku Klux Klan, and Christian Identity."

The white nationalist and neo-Nazi social media efforts, Berger found, quickly crystallized around Trump, who announced his candidacy for president with a speech calling Mexicans "rapists" and drug traffickers.

Months later, Trump told CNN's Anderson Cooper that "Islam hates us," and said "China is killing us" on trade. He compared Chicago to a war zone and urged black people to vote for him by asking: "What the hell do you have to lose?"

As president, many of Trump's early policy initiatives appealed to the white nationalists within his base - including a harsh new immigration order that would ban travel from Muslim-majority countries.

One of the architects of the travel ban, Stephen Miller, was claimed as a mentee by Richard Spencer in a Vanity Fair article published last year. Miller fiercely disputed that he and Spencer ever had any kind of relationship, however, when they were both students at Duke University.

Spencer, for his part, told reporters earlier this week that he doesn't think Trump condemned his movement when he denounced neo-Nazis, the Ku Klux Klan, and white supremacists on Monday.

"Did he say 'white nationalist?'" Spencer asked. "'Racist' means an irrational hatred of people. I don't think he meant any of us.'"

Trump did call out white nationalists by name in his explosive press conference on Tuesday, saying "they should be condemned totally" along with neo-Nazis. But many of his "alt-right" supporters - including Spencer, alt-right conspiracy theoriest Jack Posobiec, and Sputnik reporter Cassandra Fairbanks - celebrated when Trump doubled down on the claim that "many sides" were responsible for the violence in Charlottesville.

"I have never ever been so pleased with a politician," Fairbanks tweeted. "He just verbally beat their asses while telling the truth."

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