A visibly emotional Beto O'Rourke, responding to a mass shooting that has left at least 20 dead in his hometown of El Paso, Texas, said on CNN's "State of the Union" Sunday that President Trump is a "white nationalist" and that he is "encouraging" more racism and violence in this country.

"The things that he has said, both as a candidate and then as the president of the United States, this cannot be open for debate. You, as well as I, have a responsibility to call that out, to make sure that the American people understand what is being done in their name by the person who holds the highest position of public trust in this land. He does not even pretend to respect our differences or to understand that we are all created equal.

He is saying that some people are inherently defective or dangerous — reminiscent of something that you might hear in the Third Reich, not something that you expect in the United States of America — based on their religion, based on their sexual orientation, based on their immigration status, based on the countries that they come from. Calling those in Africa shithole nations and saying that he'd like to have more immigration from Nordic countries, the whitest place on planet Earth today. So again, let's be very clear about what is causing this and who the president is. He is an open avowed racist and is encouraging more racism in this country."

The big picture: O'Rourke is far from the only 2020 candidate to label Trump a racist and condemn him for his divisive rhetoric in the aftermath of the twin shootings in El Paso and Dayton, Ohio. The El Paso shooter allegedly posted an anti-immigrant manifesto online hours before opening fire at a Walmart, and he later told police that he "wanted to shoot as many Mexicans as possible," according to ABC News.

The other side: White House acting chief of staff Mick Mulvaney defended Trump against allegations of white nationalism on ABC's "This Week" and argued that O'Rourke is only making these accusations because he is running for president.

"Here's the question you can ask Beto and I would if he were sitting here. ... Look, did anyone blame Bernie Sanders for the congressional baseball game shooting? No, I don't think so. Did anyone blame Alexandria Ocasio-Cortez for the crazy guy who tried to blow up the DHS office in Washington state, taking I think a homemade bomb and an AR-15 to shoot up what he called a concentration camp, the exact same rhetoric that AOC was using? ... There's no benefit here to try to make this a political issue. This is a social issue, and we need to address it as that."

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