A group of 2020 Democrats have called President Trump a "white supremacist," an extraordinary charge at an extraordinary moment in American politics.

Why it matters ... This is a big shift from calling the president a white nationalist. Check out Merriam-Webster's definition of white supremacist: "a person who believes that the white race is inherently superior to other races and that white people should have control over people of other races."

Elizabeth Warren told the New York Times "without hesitation" that Trump gave white supremacists aid and comfort. "He’s done the wink and a nod," she said. "He has talked about white supremacists as fine people. He’s done everything he can to stir up racial conflict and hatred in this country."

Beto O'Rourke told MSNBC Trump made it "very clear" that he's a white supremacist.

Bernie Sanders told CNN's Jake Tapper over the weekend that he believes Trump is a white supremacist.

The big picture: 2020 Democrats have been driving the national conversation in the wake of last weekend's twin mass shootings in El Paso and Dayton, calling for more gun restrictions and directing much of their criticism at Trump.

O'Rourke has been one of the most vocal anti-Trump figures since El Paso's massacre Saturday. The former Texas congressman has said previously that Trump is a "white nationalist" who encourages racism and violence in the U.S.

What he's saying: Trump denies he's racist. He told reporters Wednesday he's "concerned about the rise of any group of hate." "Whether it's white supremacy, whether it's any other kind of supremacy. Whether it's Antifa," he said, referring to the far-left, anti-fascist movement. "Whether it's any group of hate."

Trump later tweeted: "The Dems new weapon is actually their old weapon, one which they never cease to use when they are down, or run out of facts, RACISM! They are truly disgusting! They even used it on Nancy Pelosi. I will be putting out a list of all people who have been so (ridiculously) accused!"

What’s next: This will put pressure on other Democrats to agree with a charge not made in a generation of American politics: that their opponent, the sitting president, believes whites are the dominant race and should control other races.

While former Vice President Joe Biden has not called Trump a white supremacist, he did say earlier Wednesday that the president "has fanned the flames of white supremacy in this nation."

Editor's note: This article has been updated with new details throughout.

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