Fox News host Tucker Carlson claimed on his show "'Tucker Carlson Tonight" Tuesday that white supremacy is a "hoax" and "actually not a real problem in America."

Why it matters: A racist manifesto complaining about a "Hispanic invasion" was posted online by a writer identified as the suspected gunman before the El Paso mass shooting Saturday. Per Axios' Jim VandeHei and Sara Fischer, white-extremist active shooters in the U.S. were responsible for 65 deaths in 7 episodes in the past 18 months.

Context: Trump has been labeled a racist for his divisive rhetoric on migrants and lawmakers of color. Such claims have escalated since the El Paso massacre.

Notably, Democratic presidential candidate Beto O'Rourke said Sunday that the president is a "white nationalist" who is "encouraging" more racism and violence in the U.S.

The big picture: While the writer of the racist 8chan post stressed that the views he expressed predated Trump's presidency, CNN analysis of Trump campaign Facebook ads shows the word "invasion" was used approximately 2,200 times.

Some Fox News hosts have come in for criticism following the El Paso shooting. According to the liberal nonprofit Media Matters for America, there have been more than 70 references on the influential network this year to an invasion of migrants and at least 55 clips of Trump calling the surge of migrants an invasion.

What they're saying: Trump condemned racism and white supremacy Monday during an address to the nation after the mass shootings in El Paso and Dayton over the weekend. "These sinister ideologies must be defeated," he said. "Hate has no place in America."

In his segment, Carlson dismissed the issue of white supremacy as "a lie" as he defended the president.

The bottom line: White nationalism is a growing threat in the U.S., as VandeHei and Sara Fischer note.

FBI Director Christopher Wray told Congress last month that the bureau made about 100 domestic terrorism arrests in the first 3 quarters of this fiscal year. Most related to white supremacy.

Go deeper: America's hate problem