"I know it's probably not good politics," said Sen. Bernie Sanders, setting up the best line of the Democratic debate, "but I think the secretary is right. The American people are sick and tired of hearing about your damn emails!"

It was the biggest applause line of the night, drawing a round of wolf whistles and cheers from the live crowd in Las Vegas, and an outpouring of support from everyone else on Twitter. The two candidates even took a break from their sparring to exchange grins, and came out from behind their podiums to shake hands.

The five Democrats on the debate stage were not overly nice: there was of shouting, attacks by name, and interrupting. And Sanders was not exempt — he's even did a bit of that classic Sanders finger wag at his opponents. But, the most resonating moments of the debate weren't moments of conflict, but when Sanders went out of his way to praise his fellow Democrats.

According to the campaign, the "damn emails" line was entirely off-the-cuff. "When you don't script somebody, they're not canned, you get lines like that that come right from the heart," Jeff Weaver, Sanders' campaign manager said after the debate. And, Weaver says, it's a good moment for both candidates.

"What it really showed is this: what he wants to do is talk about the real political issues facing the American people," Weaver said, speaking to reporters. "He would much rather have a debate with Hillary Clinton about real issues rather than... well, he said it better than I can say it."