A new ad from Our Principles PAC calls GOP frontrunner Donald Trump "unelectable" and runs together numerous racial controversies involving Trump through the years.

The most recent example was on Sunday, when Trump was asked several times by CNN host Jake Tapper about whether he disavowed support from former KKK Grand Wizard David Duke and other white supremacists, and Trump said he knew nothing about said groups and would have to "do research."

MSNBC's Morning Joe host Joe Scarborough, who has constantly congratulated himself for foreseeing Trump's viability as a candidate, called Trump's ambivalence "disqualifying."

The ad also relayed Trump's history with the "birther movement" that questioned whether President Obama was truly born in the United States, as well his questioning of how Obama got into top-tier schools. Former Face The Nation host Bob Schieffer said Trump's charge sounded like racial coding.

Seth Meyers' famed roast of Trump at the 2011 White House Correspondents' Dinner makes a cameo in the ad. Trump memorably remained stone-faced throughout Meyers' series of zingers, which included mocking Trump's profession that he had a "great relationship with the blacks."

"Unless the blacks are a family of white people, I bet he's mistaken," Meyers sad.

It also got into Trump's history with the Central Park Five and a 1970s lawsuit by the Department of Justice over federal housing discrimination.

"It's all fun, it's all a circus, it's all a rodeo, until it starts to smack of racism, and then it's no longer fun," former late-night host David Letterman says at the ad's conclusion.

Trump, after a series of Super Tuesday victories, remains the heavy favorite to capture the Republican presidential nomination.