"I think this is who Donald Trump is. And I think the American people should be very concerned about somebody who keeps changing his mind, not only on this debate, but on virtually every issue he's been asked about," Sanders said.
"Look, Donald Trump said he wanted to go forward. Then he changed his mind, said no. Then he changed his mind, said yes. Then he changed his, and he said no. Maybe we will get call in five minutes where he will say yes again," Sanders told CBS news.
Disagreeing with Trump that the Democratic primary process was rigged, Sanders however said the process was "dumb."
"I wouldn't use the word rigged, because we knew what the words were - but what is really dumb is that you have closed primaries, like in New York state, where three million people who are Democrats or Republicans could not participate, where you have situation where over 400 super delegates came on board Clinton's campaign before anybody else was in the race, eight months before the first vote was cast," Sanders said.
