Sen. Bernie Sanders Wednesday called James Carville a “political hack” two days after the former President Clinton adviser said it would be the “end of days” for Democrats if Sanders became the nominee.

"Look, James, in all due respect, is a political hack who said very terrible things when he was working for Clinton against Barack Obama," Sanders told CNN’s Anderson Cooper. "We are taking on the establishment. This is no secret to anybody."

Sanders said he is taking on President Trump, the Republican establishment as well as the Democratic establishment, “but at the end of the day the grassroots movement we are putting together of young people, of working people, of people of color, want real change.”

JAMES CARVILLE WARNS OF 'END OF DAYS' IF DEMS CHOOSE BERNIE: 'I'M NOT INTERESTED IN BEING IN A CULT!'

On MSNBC’s “Morning Joe” Monday, Carville claimed that Sanders doesn’t have a broad enough appeal to be able to beat Trump.

He said African American voters aren't interested in socialism and a revolution and "all this foolishness you hear," but instead want to be sold on a vision for how they "fit into this country."

He also referred to Sanders and his supporters as a "cult."

"There’s a certain part of the Democratic Party that wants us to be a cult," he said. "I’m not interested in being in a cult."

Former secretary of state Hillary Clinton has also piled on Sanders, claiming last month, “nobody likes him. Nobody wants to work with him, he got nothing done.”

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Many moderate Democrats have raised concerns over Sanders’ general election chances as a self-proclaimed Democratic socialist, after his strong showings in Iowa and New Hampshire where he finished first in a narrow win over Pete Buttigieg Tuesday.

Fox News' David Montanaro contributed to this report.