The truth is, Biden had been smiling for days.

Across the country, voters responded. If Democrats had tasted the revolution Sanders was offering in Iowa, New Hampshire, and Nevada, in states throughout the South they quickly turned away, and back toward the more familiar center-left politics Biden represents. Buoyed by black voters, the former vice president won early and convincing victories in Virginia, North Carolina, and Alabama. He racked up dozens of delegates in beating Sanders so handily. And even in Vermont, Sanders’s home state, Biden appeared likely to cross the 15 percent threshold needed to pick up some delegates. He went on to win Minnesota, likely thanks to Klobuchar’s endorsement, and Massachusetts, where he beat not only Sanders but a favorite daughter, Senator Elizabeth Warren.

Read: Bernie Sanders meets his biggest threat

Beating President Donald Trump is a powerful motivator for Democrats. In fact, 60 percent of Democrats, when asked whether they would prefer a candidate who agrees with them on almost all issues or one who had the best chance of beating the president, said they would prefer the candidate who would defeat Trump, according to a November Gallup poll. “The further we get into primary season, the more seriously everybody is going to take it,” one of these “electability voters,” Lisa Grant-Coffin, a 53-year-old art director, told The Atlantic at Biden’s primary-night rally in South Carolina on Saturday. “Ideology is important, but pragmatism is important. You can’t do anything if you’re just yelling on the corner,” she said. “You have to be in the office."

The Democrats’ desperate need to beat Trump is part of why former New York City Mayor Michael Bloomberg was able to quickly rise in the polls. He flooded ad markets with one main message: He was the one who could topple Trump.

For the past several months, Bloomberg has been the wild card. He made the risky move of skipping all four early nominating states to bet it all—or at least half a billion dollars of his personal fortune—on Super Tuesday. For a brief moment, the strategy seemed to be working. He rose to the top tier in polling for many of the contests. Then came a miserable Nevada debate and a reconsideration of how he would actually perform against Trump. The electability voters who once believed that Biden might self-destruct flooded back to the vice president. And early tonight, it became clear that Biden’s strongest constituency—black voters—would continue to support him in large numbers. According to Virginia exit polls, Biden won 63 percent of the black vote in that state, compared with 18 percent for Sanders and just 10 percent for Bloomberg.

“A lot of black voters, especially southern black voters, aren’t looking for a revolution,” Christina Greer, an associate professor of political science at Fordham University, told The Atlantic in an interview tonight. “The reason why a lot of older black voters are conservative—as in, conservative in picking a candidate—is because they know what this country is capable of … Sure, some people will agree with the need for a revolution,” but many others may be wary.