“Your agenda has promised free health care for everybody, free college tuition, and to pay off peoples’ college loans. The price tag for that is estimated to be $60 trillion dollars over ten years. Is that correct?” asked Norah O’Donnell of CBS Evening News.

“Well look, we have political opponents…” Sanders began before being cut off and pressed on the question.

“You don’t know how much your plan costs?” O’Donnell responded.

“You don’t know. Nobody knows. This is impossible to predict,” Sanders conceded, leaving O’Donnell stunned.

“You’re going to propose a plan to the American people and you’re not going to tell them how much it costs?” O’Donnell exclaimed.