WASHINGTON -- Former reality TV star Donald Trump denounced the Ku Klux Klan at Thursday night's GOP presidential debate in Detroit. It's the latest development in an increasingly surreal Republican primary campaign, where a white supremacist organization that has promoted hatred and violence for over a century is a natural topic of discussion.

"I totally disavow the Ku Klux Klan, I totally disavow [former KKK Grand Wizard] David Duke, I've been doing it now for two weeks," Trump said, responding to a question from Fox News moderator Chris Wallace about his views on white supremacists.

Trump's nativist platform, which includes building a wall on the Mexico-U.S. border, and banning Muslims from traveling to the United States, clearly speaks to them. Duke said last month that a vote against Trump is "treason to your heritage." A white nationalist Super PAC paid for robocalls to support him, and a pro-white radio host boasted about landing an interview with his eldest son, Donald Trump, Jr. (Trump Jr. claimed on Wednesday he wasn't aware whom he was speaking with.)

"Everybody knows Trump is the only one who actually promises to take action on these open borders," Robert Whitaker, a lifelong segregationist who promotes the idea that diversity leads to “white genocide,” told The Huffington Post on Wednesday.

Trump has not only been slow to denounce white nationalist support, but he has actively fanned the flames. He initially refused to disavow Duke, blaming it on a faulty earpiece amid an onslaught of public criticism, including from his rivals. "You say, 'David Duke' to me, I say, 'racist,' immediately," Florida Sen. Marco Rubio said at a rally last month.

On Thursday, Trump pointed out that he had already disavowed Duke on his Twitter account. "When I do something on Twitter, everybody picks it up, it goes all over the place, but when I did this one, nobody ever picks it up," he said. "Take a look at my Twitter account."

Trump once retweeted a user with the handle, "WhiteGenocideTM."

He is not the first GOP presidential candidate to earn white supremacist support. Earl Holt III, president of the Council of Conservative Citizens, a white nationalist organization, donated thousands to the presidential campaign of Senator Ted Cruz (R-Texas) last year. (After it was publicized, Cruz donated to the Mother Emanuel Hope Fund, which provided financial support to the families of victims of the shooting at a historic black church in Charleston, a city spokesman confirmed.)

Democrats, meanwhile, aren't buying Republicans' grandstanding about the KKK while they are obstructing other efforts to combat racism and inequality.

"The sanctimony that was displayed in terms of ‘Oh, my gosh, can you believe he said that?’ -- it’s stuff that we hear around here all the time," House Minority Leader Nancy Pelosi (D-Calif.) told reporters on Thursday.