Concord, New Hampshire—Two days before New Hampshire’s first-in-the-nation primary, Bernie Sanders challenged a crowd of young supporters gathered at Keene State College to lift him to victory: “Let us win here in New Hampshire, let us win the Democratic nomination, let us defeat Donald Trump, let us transform this country, let us go forward together.”

On Tuesday, New Hampshire did its part. Now, the senator must convince voters in upcoming caucus and primary states that he will make the rest of the pieces fall into place.

The Sanders campaign must go beyond “Bernie Beats Trump” sloganeering and deliver a comprehensive and convincing argument that the senator is the most electable contender.

It certainly helps to have won the first primary. With 95 percent of precincts reporting, the networks declared Sanders the winner, with 26 percent of the vote. Former South Bend mayor Pete Buttigieg, who moved into the top tier of the competition after a tight finish with Sanders in Iowa, was in second with 24 percent. Minnesota Senator Amy Klobuchar surged into third place with 20 percent. It was a steep drop off to fourth place for Massachusetts Senator Elizabeth Warren, who had 9.4 percent. Former vice president Joe Biden, who fled to the upcoming primary state of South Carolina before a “victory party” that wasn’t, finished fifth with 8.5 percent. Sanders, Buttigieg, and Klobuchar won delegates, Warren and Biden did not.

The New Hampshire results were not so decisive as they were for Sanders when he swept the state’s 2016 primary. But they were still reassuring for the senator, who secured the first clear win of 2020 after a stumbling start in Iowa.

At the same time, however, New Hampshire handed Sanders a message about what matters most to primary voters in that state and beyond its borders. “About 6 in 10 Democratic voters in exit polls in New Hampshire said they preferred a candidate who can beat President Trump, rather than one who agrees with them on the issues,” explained a Washington Post analysis. Iowa entrance polls had that number at 61 percent.

Of the 63 percent of New Hampshire voters who said they want a candidate who can beat Trump, 28 percent backed Buttigieg, while 21 percent were Sanders voters and 20 percent were for Klobuchar. Biden and Warren each got 11 percent. Among the “agrees with you on the issues” crowd, Sanders was the big winner, with 39 percent, while Buttigieg was at 22 percent and no one else was above 11 percent.

But there’s a twist. While almost half of voters said Sanders was “too liberal,” overwhelming majorities of those same voters embraced the issues most closely identified with his campaign. The Post noted:

About 6 in 10 New Hampshire Democratic primary voters in preliminary exit polls said they support replacing all private health insurance with a single government plan for everyone…

About two-thirds of Democratic voters in early exit polling said they support making tuition free at public colleges and universities…

If the issues that Sanders has been raising have such broad appeal, why then is he considered “too liberal”? The answer has a lot to do with how he’s covered by media outlets that often go out of their way to portray Sanders, and to a lesser extent Warren, as “too extreme.” But it also has to do with the messaging that comes from the candidate and his campaign. “Bernie Beats Trump” can’t be just a motto on a button; it has to be in his campaign’s DNA.

Klobuchar’s campaign has figured out that message, and it showed in New Hampshire. She finished the primary campaign telling crowds, “I’ve won every race, every place, every time, all the way down to fourth grade.” TV commentators relish lines like that, and the Minnesota senator is sure to enjoy plenty of good press as she heads toward contests in Nevada, South Carolina, and the 14 Super Tuesday states that vote March 3.

It is unlikely that the media will be so friendly to Sanders. So it will fall to him to stake a claim on the “electability” label.

Make no mistake, he can stake that claim, as savvy Democrats have recognized. Congressional Progressive Caucus cochair Mark Pocan, a Wisconsin Democratic who did not endorse in the 2016 Democratic contest between Sanders and former secretary of state Hillary Clinton, traveled to New Hampshire this year to make stops across the state on behalf of the Vermonter. “I’m here to speak for the candidate who I know can defeat Donald Trump,” Pocan told a crowd in Hudson. Arguing that Sanders is best positioned to win battleground states such as Michigan, Pennsylvania, and his native Wisconsin, Pocan says, “The electability discussion is very different outside Washington. You don’t hear people dismissing Bernie Sanders. You hear people saying, ‘You know, this is the guy who could beat Trump.’”

Another key Sanders backer, US Representative Alexandria Ocasio-Cortez told a crowd of 7,000 in Durham the night before the primary, “Let’s talk about November!” said AOC. “In every poll, Bernie beats Trump.” Sanders does, indeed, beat Trump in national and state polls. The Real Clear Politics average of recent national surveys has Sanders at 49.3 to 45 for Trump, and a new Quinnipiac survey has Sanders opening up a wide 51-43 lead over the president. By comparison, the RCP average has Buttigieg at 46.1 to 45.1 for Trump. Klobuchar is up 46-43.4, while Warren leads Trump 47.8 to 45.

After spending hundreds of millions of dollars positioning him as a November prospect, Bloomberg beats Trump 49.8-43.8 in the RCP average. Biden’s numbers have also been solid against Trump, although his weak finish in New Hampshire will make it hard for the former vice president to maintain them.

Clearly, Sanders can make a credible argument for himself as an electable candidate. But he will have to sharpen that message going forward.

Coming out of New Hampshire, as the senator makes stops in Super Tuesday states such as North Carolina and Texas, he will find himself going head to head with contenders who argue that Sanders—as a democratic socialist with a bold agenda for Medicare for All, making higher education free for all, and addressing the climate crisis with a plan based on Green New Deal principles—is just too radical. Klobuchar, who raised more than $3 million in online donations after a strong performance in last Friday’s debate, has been selling herself as the candidate who can reach swing voters—with the message: “If you are tired of the extremes in our politics and the noise and the nonsense, you have a home with me.”

Pundits love that line. But it misses something fundamental about the 2020 race. Instead of building his campaign around appeals to a dwindling universe of “swing” voters, Sanders is talking about building the electorate out to include new voters—many of them young, many of them from low-income and historically disenfranchised communities. In Iowa and New Hampshire, he has been successful in attracting young voters. He also had notable success mobilizing Latino voters and diverse immigrant communities in Iowa. In the upcoming Nevada caucuses and the South Carolina primary, he’ll have to keep proving himself.

Actor and author John Cusack, who campaigned for Sanders in New Hampshire, argues that the candidate and his supporters must now amplify the message that his ideas represent the new mainstream. “The ‘center’ has moved to Bernie on policy,” says Cusack, who notes that all the candidates are discussing ideas that were popularized by Sanders in 2016.

This amplification doesn’t involve abandoning positions or principles, as presidential contenders frequently do when they gain traction. Rather, Sanders must define his campaign as a new center where Democrats, independents, and millions of new voters have a place—in much the way that Franklin Delano Roosevelt did as he crafted a sprawling “New Deal Coalition” that reached across what had been lines of division to welcome the great mass of Americans who wanted a new politics.