Last week in Iowa, former Vice President Joe Biden explained why Democrats should nominate him for president. “Some things are just a self-evident contrast,” he told reporters, taking a dig at Pete Buttigieg, the former mayor of South Bend, Indiana. “I’ve gotten more than 8,600 votes in my life.”

That was a reference to the relatively small population of South Bend, where Buttigieg won his first election with fewer than 11,000 votes and his second with barely 8,500. Biden was raising a legitimate question: Why should Democrats entrust their nomination to the 38-year-old former mayor of a minor city? Why should they believe that Buttigieg, in a race against President Donald Trump, could perform as effectively as Biden?

On Monday night, Buttigieg answered that question. He crushed Biden in the Iowa caucuses. As of Wednesday morning, with more than 70 percent of precincts reporting, Sen. Bernie Sanders was narrowly leading the popular vote, thanks to big margins in left-leaning parts of the state. But Buttigieg, by assembling a broad coalition of progressives, moderates, suburbs, and small towns, was winning the “delegate equivalent” count—Iowa’s version of the Electoral College. Biden was clinging to fourth place, behind Sen. Elizabeth Warren and barely ahead of Sen. Amy Klobuchar, with fewer votes than Buttigieg won in his two elections in South Bend.

In the wake of this drubbing, it’s fair to ask Biden’s question in reverse: Is Buttigieg the stronger candidate? For Democrats seeking an electable nominee, is Buttigieg the safer bet?

There are reasons to be skeptical. Iowa is just one state. It’s Midwestern, like Buttigieg, and it’s very white. In raw numbers, Sanders won the most support at the caucuses, and he’s leading the polls in New Hampshire. Biden still leads the field in national surveys, and he has generally outperformed other Democrats in matchups against Trump. But the Iowa entrance polls and caucus results make a case for Buttigieg, not Biden, as the candidate who can fend off Sanders and take down Trump.

Several candidates, including Biden and Klobuchar, have promised to beat Trump by building a coalition that reaches beyond the left. But in Iowa, Buttigieg proved that he can put together that kind of coalition. He won decisively among caucusgoers who called themselves “somewhat liberal”—a segment that represented more than 40 percent of attendees—and he tied Biden for the lead among moderates. Among independents, he trailed Sanders but outpolled Biden. As of Wednesday morning, Buttigieg was winning 60 of Iowa’s 99 counties. Sanders had 18 counties. Biden had seven.

Buttigieg did well in nearly every demographic. He was the first choice among women and the second (behind Sanders) among men. He was the first choice among people ages 45 to 64, the second choice among those ages 30 to 44, and—contrary to expectations—the second choice among those ages 17 to 29. He came in first among caucusgoers who had college degrees and second among those who didn’t. He also performed better than expected among nonwhites. Sanders won that constituency easily, but Buttigieg, at 15 percent, led the pack of candidates who trailed behind.

On issue after issue, Buttigieg was either the favorite or second favorite candidate. Among caucusgoers who cared most about health care, he tied for the lead with Sanders. Among those who cared most about foreign policy, he came in second to Biden. Among those who focused on electability, he tied for the lead, drawing 24 percent to Biden’s 23 percent. Sanders got 31 percent of first-time caucusgoers, but Buttigieg was next with 25 percent. In precincts where supporters of marginal candidates had to disband and move to a second choice, the candidate they chose—twice as often as any other candidate—was Buttigieg. He won by being broadly acceptable.

Sanders did well, but he lost nearly half the people who had caucused for him in 2016. He also didn’t generate the extra turnout he had promised. And Biden grossly underperformed his polls, falling below 15 percent in many precincts—the threshold at which a candidate’s supporters have to disband—contrary to his advisers’ predictions. On most issues and among voters younger than 45, Biden came in fifth, behind Warren and Klobuchar.

Few Democrats are excited about Biden. Among caucusgoers who cared more about candidates’ positions than about electability, only 5 percent chose him. He’s been propped up by high name identification, endorsements, his association with former President Barack Obama, and a general feeling among Democratic voters that he stands the best chance of beating Trump. But if he can’t beat the former mayor of South Bend and two senators who were stuck in an impeachment trial, maybe he’s not the safe bet.

Update, Feb. 6, 2020, 1:30 p.m.: Since I published this piece, Iowa has released more results. Accordingly, we have changed the headline from “How Pete Won” to “How Pete Beat Joe.” Nothing in the article has been changed. As of this update, with 97 percent of precincts tabulated, Buttigieg had 26.2 percent of state delegate equivalents, Sanders 26.1, Warren 18.2, and Biden 15.8.