Hillary Clinton had a smooth night playing her cards in Las Vegas.

Bernie Sanders didn't expand his chips, eagerly embracing the socialist label and slamming the rich.

The other candidates were an afterthought and, as in the case of Lincoln Chafee declaring himself a block of granite, sometimes weird.

The CNN debate, perhaps benefiting from low expectations, alternated between wonky and enlightening.

With Hillary and Bernie broadcasting in advance that they wouldn’t attack each other personally and Anderson Cooper vowing there would be no “gotcha” questions, many folks envisioned a snoozefest. No one was expecting a Trump-like audience of 24 million viewers. And Trump pronounced the debate “boring” in advance, providing an entertaining diversion by live-tweeting the thing (no wonder “Saturday Night Live” has booked him for next month).

With the also-rans—Martin O’Malley, Jim Webb and Chafee—not cracking 1 percent in the polls, the debate simply lacked star power.

In what sounded a bit like reading the talking points, Hillary kept saying she would be the first woman president—both  in response to questions about whether she’d run Barack Obama’s third term and why the country shouldn’t elect an outsider. It was her get-out-of-jail-free card. She even made a joke about taking longer during a bathroom break.

Cooper had many pointed questions. He asked Sanders how a socialist could be elected president—Bernie talked about the rich having too much, and admired the societies of Norway and Denmark—enabling Clinton to jump in and claim the mantle of capitalism.

Hillary was also able to draw a sharp contrast when Cooper asked whether Sanders was tough enough on guns: “No, not at all ... It’s time the entire country stood up against the NRA ... Senator Sanders voted five times against the Brady bill.”

Sanders, mentioning twice that he represents a rural state in Vermont, countered with “all the shouting in the world is not going to do what I hope all of us want—which is keep guns out of the hands of people who shouldn’t have guns and end this horrible violence that we’re seeing.”

Gun control is one of the few issues where Hillary is to Bernie’s left, having previously moved toward his more liberal stance on trade and the Keystone pipeline. He cannot match her on the gun-regulation issue, which is far more popular with Democrats than Republicans, and he didn’t try.

Clinton didn’t pause when the moderator asked if she keeps changing her political identity. She said that, “like other human beings,” her view evolves as she takes in new information—and volunteered her switch on the Pacific trade deal, preempting a possible attack line.

Foreign policy was difficult terrain for Sanders. He challenged Clinton’s idea for a Syria no-fly zone as dangerous and kept defaulting to the fact that he had opposed the Iraq war—with the clear implication that Hillary did not. The senator was finally forced to declare “I am prepared to take this country into war” if necessary.

Hillary’s shift to the left was clear in the opening minutes, as she ticked off her desire to raise wages, adopt family leave, make the rich pay more in taxes and address climate change, while barely taking a breath.

Clinton and Sanders took turns bashing Wall Street, Sanders a bit more passionately. When Bernie turned to Hillary and said “Congress doesn’t regulate Wall Street, Wall Street regulates Congress,” his fans must have whooped and hollered. But for most viewers it was probably a wash.

Hillary benefited from the fact that Cooper didn’t bring up the email scandal for nearly an hour. She gave her standard made-a-mistake answer and didn’t seem rattled.

Sanders, who speaks in a shout, had the sound bite of the night when he turned to the front-runner and said, “The American people are sick and tired of hearing about your damn emails.” The Vegas crowd loved it, and Sanders seemed like he was avoiding cheap shots.

But Sanders, who has little minority support, answered a video question about whether black lives matter or all lives matter by saying: “Black lives matter.” That was an obvious bit of pandering.

Hillary Clinton went into the debate as the front-runner and emerged relatively unscathed as the front-runner. It may have been the longest she’s been on television all year without having to talk much about her email—and that has to be regarded as hitting the Las Vegas jackpot.

Howard Kurtz is a Fox News analyst and the host of "MediaBuzz" (Sundays 11 a.m. and 5 p.m. ET). He is the author of five books and is based in Washington. Follow him at @HowardKurtz. Click here for more information on Howard Kurtz.