While these are still the early days of the Democratic primary, things are plainly not going well for Bernie Sanders. Joe Biden’s landslide victory in South Carolina and commanding performance on Super Tuesday have made him both the delegate leader and the presumptive front-runner for the Democratic nomination, a position few predicted he’d be in as recently as a week ago. For that, he can thank media coverage of South Carolina Congressman James Clyburn’s endorsement, which likely bolstered his margins in the state and set in motion the suspension of the rival moderate campaigns, the televised endorsements of those candidates, and the consolidation of the party’s rank and file behind him on Tuesday night. Sanders, meanwhile, has had to contend with worrying cracks in his campaign’s strategy. The long-anticipated explosion in turnout from young and potentially progressive but disengaged voters simply hasn’t happened; those new voters who did show up for Tuesday’s races went overwhelmingly for Joe Biden.

It’s become an article of faith that Sanders needs a miracle to win, but it’s worth being clear about where the race actually stands. As of Saturday afternoon, there’s a gap of 91 pledged delegates between him and Biden. That might seem like a small deficit, but closing it will require Sanders to dramatically improve his performance in the upcoming primaries. To do this, he has to significantly broaden his coalition, winning over many more Democrats who might not consider themselves progressives, including the moderate suburbanites and older African Americans who put Biden on top in so many places on Super Tuesday. There’s not much time to shift gears before the next slate of races on March 10. An earned media coup of some kind might be helpful in dislodging Biden’s wins from the headlines before those voters go to the polls. But whether or not fortune smiles on Sanders within the next few days, his campaign now faces a critical test that will speak to his capacity as a politician to weather the political challenges a Sanders administration would face.

That test—making meaningful changes in both his political style and the substantive emphasis of his campaign to win over ordinary Democrats without alienating many of his existing supporters—is one Sanders can pass with some creative thinking. The campaign is already toeing in the right direction. An ad featuring praise from Barack Obama was released earlier this week, for instance, and Sanders reportedly wants to talk up his plan to expand Social Security, which might increase his support among older Democrats. But the task ahead for Sanders isn’t just patching up vulnerabilities within an already strong campaign. He has to pull off a full reset—reinventing a campaign that was never built to win a majority of the Democratic electorate in an undivided field in the first place, and getting the Democratic rank and file to think differently about Sanders as a political figure.

The first hurdle to overcome is the electability question.

The first hurdle to overcome is the electability question. However much they might like him as an individual, and whatever they think about his policy positions, many Democratic voters simply do not believe Bernie Sanders can defeat Donald Trump in November. That impression has been reinforced by his losses this week, which have called into question whether Sanders can truly inspire the unprecedented levels of turnout he’s repeatedly called necessary for a Democratic victory. But it has never actually been true that Democrats need a historically anomalous level of turnout and a tidal wave of new voters to win. The basic path to victory for both Sanders and Biden remains winning back some of the white working-class voters in industrial states who responded to Trump’s right populism, and bumping up turnout from African Americans just enough so that Trump isn’t as competitive in states like Michigan and Pennsylvania as he was in 2016. Boosting Latino turnout to put states like Arizona and Texas in play wouldn’t hurt, either.

As far as the white working class is concerned, Sanders has been a bit more reticent than his most ardent supporters in making the case that there are Trump voters disenchanted with this administration that Democrats can pull back in with the promise of economic opportunity. That should change, and he should make the argument without apologizing for or explaining away racism within the constituency. He can argue, in fact, that given the difficulty of the task, only his agenda, not Biden’s, is bold enough to truly break through with some Trump supporters.