Days after former Clinton adviser James Carville said he was “scared to death” of Bernie Sanders capturing the Democratic presidential nomination, the Independent Vermont senator returned fire, calling the longtime Democratic operative a “political hack.”

Interviewing Sanders on CNN Wednesday night, anchor Anderson Cooper noted that Carville claimed that Democratic voters weren’t interested in being in a “cult” and “socialism” and wouldn’t support a 78-year-old “screaming in a microphone about the revolution.” (Carville, for the record, endorsed Sen. Michael Bennet (D-CO) for president, who dropped out after getting just 0.3 percent of the vote in New Hampshire.)

“I wanted to give you a chance to respond,” Cooper told Sanders.

“Look, James, with all due respect, is a political hack who said very terrible things when he was working for Clinton against Barack Obama,” Sanders, fresh off his New Hampshire primary win, replied. “I think he said some of the same things. Look, we are taking on the establishment. This is no secret to anybody. We’re taking on Wall [Street]—I guess the former head of Goldman Sachs attacked me yesterday.”

“Yeah, he had some unkind things [to say] as well,” Cooper noted, referencing Lloyd Blankfein’s claim that Sanders is as polarizing as President Donald Trump and would “ruin our economy.”

After noting that Wall Street, the pharmaceutical industry, insurance companies, and the military-industrial complex all hate him, Sanders added that he’s also “taking on Trump, the Republican establishment, Carville and the Democratic establishment.”

“But at the end of the day, the grassroots movement that we are putting together of young people, of working people, of people of color, want real change,” the presidential hopeful concluded.