FILE - Counter-protesters yell across the street at city hall during a neo-Nazi rally at the Jackson County Courthouse in Kansas City, Missouri, Nov. 9, 2013.
FILE - Counter-protesters yell across the street at city hall during a neo-Nazi rally at the Jackson County Courthouse in Kansas City, Missouri, Nov. 9, 2013.

A new study has concluded that white nationalists and self-identified Nazi sympathizers, mostly in the United States, are using social media with "relative impunity," often far surpassing the Internet interest in pronouncements of Islamic State militants.

The report, by George Washington University's Program on Extremism in Washington, showed Thursday that major American white nationalist movements added about 22,000 followers on Twitter since 2012, about a 600 percent growth. The study said the white nationalists surpassed Islamic State's usage "in nearly every social metric, from follower counts to tweets per day."

The research center said the most popular theme among the Twitter postings related to the concept of "white genocide," the suspicion that the "white race" is "directly endangered by the increasing diversity of society." It said white nationalist activists tweeted hundreds of times a day using repetitive hashtags and slogans advancing the notion of the diminishing fortunes of whites.

The university study described the followers of white nationalists on Twitter as "heavily invested" in the U.S. presidential campaign of Republican Donald Trump, a real estate mogul seeking his first elected office in the November contest against Democrat Hillary Clinton, a former U.S. secretary of state. The report said that in April, three of the top 10 hashtags for both white nationalist and Nazi sympathizers related to Trump's campaign.

Trump has centered his campaign on strict enforcement of U.S. immigration laws, deportation of millions of undocumented immigrants living in the country and construction of a wall along the southern U.S. border with Mexico to thwart the stream of migrants from entering the country.  He has disavowed the support of David Duke, the one-time imperial wizard of the white-supremacist Ku Klux Klan group, but Duke praised Trump's speech Wednesday calling for tough border control measures if he is elected president and assumes office next January.

"White nationalist users referenced Trump more than almost any other topic," the report said, "and Trump-related hashtags outperformed every white nationalist hashtag except for #whitegenocide."

It said that white nationalists and Nazis had "substantially higher follower counts" than those following Islamic State supporters and tweeted more often. But it said that some of the white supremacists' numerical advantage was attributable to the fact that managers of some social media accounts have aggressively sought to purge links to Islamic State networks.

The report said that white nationalist terrorism has increasingly been linked to online activity. It cited two horrific mass killings in which the suspects had made extensive use of Internet accounts, Dylan Roof, a white nationalist charged with killing nine black people at a South Carolina church in 2015, and Anders Breivik, the right-wing Norwegian terrorist who killed 77 people in 2011.