'So much worse than Willie Horton': Historian explains why Trump's latest ad might be the most racist ever

President Donald Trump's racist new ad that portrays undocumented immigrants as psychotic killers is drawing fierce condemnation from all corners -- and even from some of his fellow Republicans.

Princeton historian Kevin Kruse, in a lengthy Twitter thread, breaks down the reasons why the new Trump ad may be the most racist TV ad he's seen -- even worse than the infamous Willie Horton ad that aired in 1988.

Kruse begins by noting how infamous Republican campaigner Lee Atwater at the time knew that his ads tying Democratic presidential nominee Mike Dukakis to black convict Willie Horton would be seen as racist, which was why he outsourced their funding to a third-party group called "Americans for Bush."

The ad was so racist, Kruse documents, that Atwater actually felt the need to apologize for it on his deathbed.

Trump, Kruse says, feels no need to distance himself from the racism in his ad -- and has even pinned it to his Twitter profile.

"This new ad is coming directly from the personal Twitter account of the president himself," Kruse writes. "It isn't just that the president of the United States is personally pushing white nationalist politics in its ugliest and crudest form, it's that he's doing it proudly and with purpose. That is so, so much worse than 'Willie Horton' ever was."

Read the whole thread below.