Bernie Sanders is leading. But he’s not winning, and there’s a huge difference.

The far-left Sanders is now the improbable—and to some, alarming—frontrunner in the Democratic presidential contest, with a sizable lead in polls over the moderates Joe Biden, Mike Bloomberg, Amy Klobuchar and Pete Buttigieg. Many forecasters think Sanders will prevail in enough primary states to have an insurmountable lead by mid-March.

But winning the Democratic nomination requires a majority of the votes, and Sanders isn’t close to that. In early voting states he’s won about 25% of the votes, with most of the rest split among five other candidates. That’s roughly the same approval rating Sanders has among Democratic votes nationwide—and it’s not nearly enough to clinch the Democratic nomination.

Candidates tend to consolidate votes as the primaries progress and most of the competition drops out. But with self-funding Mike Bloomberg and at least one other moderate candidate likely to go the distance, Sanders will probably find the path to a majority victory blocked.

That’s why Sanders is now the only candidate arguing that whoever wins a plurality of votes should be the nominee. But there’s another way Democrats could produce a convincing victor, who, by the way, isn’t Sanders: All but one of the moderates could quit, and align themselves behind one remaining candidate.

Sanders looks far less invincible when breaking down the vote for the four to five moderates (including Tom Steyer) and the two leftists, Sanders and Elizabeth Warren. In Iowa, the Biden moderates got 54% of the vote while Sanders and Warren got 44%. In New Hampshire, the moderates got 56% while the leftists got just 35%, with several lesser candidates getting a few percentage points. Moderates are winning, overall. They’re just splitting the vote among too many people to allow any single candidate to stand out.

Sanders is also doing worse, so far, than he did in 2016, when he won 49.6% of the vote in Iowa and a stunning 60.4% in New Hampshire. There were fewer candidates overall in the 2016 primaries, but Sanders’ much weaker showing in 2020 suggests there might be a ceiling on his support within the Democratic party. That could portend a disastrous showing if Sanders were to face President Trump in the general election, with many disgusted Democrats possibly staying home and Independents looking for a reason to vote against Trump voting against Sanders instead.

If Biden, Bloomberg, Buttigieg, Klobuchar and Steyer formed a cartel to nominate just one of them to beat Sanders, who should it be? Process of elimination suggests Bloomberg is better as a funder than a candidate, Biden is too fumbly and old, Steyer too marginal, and Buttigieg too unproven. That leaves Amy Klobuchar, 59, who has a strong resume as a prosecutor and senator from Minnesota. Her Midwestern roots could help with crucial swing states such as Michigan and Wisconsin. As a woman who’s not Hillary Clinton, she might be a persuasive alternative—especially among Independents—to Trump in the general election.