Vermont Sen. Bernie Sanders argued on “State of the Union” Sunday that former Secretary of State Hillary Clinton is “the candidate of the Democratic establishment” after receiving criticism from Hillaryland over his left-wing positions.

Sanders hit back at comments from Sen. Claire McCaskill, a Clinton supporter, who called the self-avowed socialist “extreme” and “too liberal” for the American voting electorate. (RELATED: Hillary Surrogate McCaskill Attacks ‘Extreme,’ ‘Too Liberal’ Bernie Over ‘Socialist’ Views)