See Bernie Sanders Talk Trump Debate, Superdelegates on 'Real Time'

"This guy is a pathological liar. And I don't mean to be malicious, but that is just the damn truth," Vermont senator says of Trump

Bernie Sanders appeared on ;Real Time With Bill Maher; to discuss superdelegates, his platform and why he'd love to debate Donald Trump.

Ahead of the crucial June 7th California primary that could tip the balance of the Democratic presidential nomination, Bernie Sanders appeared on Friday's Real Time With Bill Maher to discuss superdelegates, his platform and why it's hard to formulate a strategy to defeat Donald Trump come Election Day. "He is so unpredictable because he lies all the time, because he changes his mind all the time; what he said yesterday is no longer valid today. How do you deal with that reality?," Sanders asked.

"This guy is a pathological liar. And I don't mean to be malicious, but that is just the damn truth," Sanders warned of Trump. "He would be not only an embarrassment, he would be a real danger to this entire world if he were to become president."

Earlier in the week, Sanders challenged Trump to a debate, an invitation the mogul toyed with accepting before issuing a statement that said it "seems inappropriate that I would debate the second place finisher," noting Hillary Clinton's lead over the Vermont senator. While Trump did "chicken out" for now, Sanders is hopeful he'll change his mind, again.

"I would have loved! First, he said he would do it, then he said he wouldn't do it. Then he said he would do it, then he said he wouldn't do it. So I would hope if he changed his mind four times in two days, change it a fifth time," Sanders said. "Trump claims to be a real tough guy, pushes people around. Hey Donald, come on up, let's have a debate about the future of America."

Sanders went on to discuss the important role California, America's most populous state, plays in determining who will be the Democratic presidential candidate, the issue of Clinton-leaning superdelegates and, briefly, Clinton's ongoing email scandal. In light of new developments in that situation, Maher offered Sanders a pulpit in which to attack Clinton over the scandal, and once again the senator declined.

"There is enormous frustration on the part of the American people with the way we do politics in this country. Most politicians, they'll say 'I'm great, you're terrible, vote for me, the other guy is the scum of the earth, blah blah blah.' But you know what? People are hurting in this country," Sanders said. "The middle class is disappearing. We got a lot of poverty, we don't have health care for all people. People want us to talk about their lives and their issues and not just spend our whole lives attacking our opponents."