An interview with the head of the Democratic National Committee quickly become uncomfortable Thursday night when she did not answer: "What's the difference between a Democrat and a socialist?"

At first, Rep. Debbie Wasserman Schultz, D-Fla., laughed at the question from MSNBC's Chris Matthews.

"I used to think there was a big difference," Matthews said. "What do you think it is?"

"The difference between …" she began, before Matthews jumped in.

"… the difference between a Democrat, like Hillary Clinton, and a socialist, like Bernie Sanders," Matthews said.

"The more important question is what's the difference between being a Democrat and being a Republican …" she said before Matthews cut her off.

"What's the bigger difference, what's the big difference between a Democrat and a socialist? You're chairman of the Democratic party — tell me the difference between you and a socialist."

"The relevant debate that we'll be having over the course of this campaign is what's the difference between a Democrat and a Republican," Wasserman Schultz said. "And the difference between a Democrat and a Republican is that Democrats fight to make sure that everybody has an opportunity to succeed, and the Republicans are strangled by their right-wing extremists."

Given the popularity of self-described socialist and Democrat presidential candidate Sen. Bernie Sanders' message, Matthews asked if he would speak at the Democratic National Committee convention. She replied that he would, but when Matthews pressed her on whether he would speak during primetime or "when nobody's watching," she was unable to answer.