The feel-good days of the presidential primary season, with its parades and door knocks and small-town quirks, are about to come to a sudden and jarring end. In just two weeks, the Democratic race will transition overnight from the charming theaters of the early caucus and primary states into a full-scale national campaign, dominated by Gross Ratings Points and pre-roll ads and media appearances instead of handshakes and whimsy. Reporters accustomed to daily press gaggles will begin to see the candidates more on a Delta backseat television than in person. More than a dozen states and territories will vote on Super Tuesday, little more than two days after the polls close in South Carolina’s primary. That short window, every four years, shines a harsh light on whoever emerges from the first four states with a pulse. It reveals which campaigns are serious built-to-last enterprises, and punishes the ones that are flash-in-the-plan flukes, destined only for Wikipedia entries about the 2020 primary race.

It’s tempting to follow this chapter of the Democratic race by watching the polls, for signs of bounces and momentum. But a grim truth is that Democrats should be looking at another metric—money—that says much more about where this race is going. And barring huge surprises or upset comebacks in Nevada or South Carolina, the money suggests something rather obvious: The Democratic primary is careening toward a head-to-head clash between Michael Bloomberg and Bernie Sanders, currently the only two candidates with the cash and constituencies to push their candidacies beyond the first four states and Super Tuesday. Who else can scale up? “This is a huge issue,” said David Axelrod, the former Barack Obama adviser. “The cost of competing across 14 states is astronomical and the remaining candidates will expend most of their limited kitties to get there. For Bloomberg, the Super Tuesday ante is lunch money. He will be able to communicate at a high level everywhere. Bernie has a reliable, renewable war chest and universal recognition. For the others, they have to hope to catch a wave of publicity and dollars off of unexpected showings in Nevada and South Carolina.”

Rufus Gifford, a Democratic fundraiser who held senior finance jobs for both of Obama’s campaigns, said he thinks there will be three finalists for the nomination in the end. “But Bernie and Bloomberg are definitely going to be two of them,” said Gifford. “It’s because they have money. They have resources. It’s hard to think of who else will be viable.” Bloomberg is a sudden new arrival at the center of the political conversation, capitalizing on Joe Biden’s stumbles and drawing attacks from President Donald Trump, thanks to a self-funded spending spree that’s never been seen in national politics. Bloomberg has built an almost 50-state campaign from scratch, spending almost $300 million on television ads and roughly $50 million on digital ads, saturating YouTube ads to the point where there are now teenagers on TikTok reciting his ad scripts by heart. He’s now in third place nationally, barely trailing Biden and cutting into his support among black voters. Sanders, meanwhile, has a first place hold in the national polls and a burst of momentum thanks to back-to-back victories, however narrow, in Iowa and New Hampshire. A small-dollar vacuum cleaner, Sanders collected over $120 million since joining the campaign last year, from over 1.4 million individual donors. He raised $25 million in January, not nearly as much as Obama did after winning Iowa in 2008, but more than anyone else in the Democratic field. Much like Donald Trump, Sanders can go back to his dedicated supporters again and again for money, the only Democrat in the race with that kind of click-to-donate power.

Among the rest of the Democrats, only Pete Buttigieg—slightly ahead of Sanders in the delegate chase—has proven himself a durable fundraiser, working the big-donor circuit as hard as his email list. He has a packed fundraising schedule over the next two weeks. But Buttigieg has to show growth among nonwhite voters. His donor support may shrivel if he doesn’t. “Donors are the consummate CNN and MSNBC viewers, they watch media trends, they pay attention to the buzz,” said Gifford. “They invest their money with all that in mind. If the narrative out there after South Carolina and Nevada is that Pete can’t win voters of color, his donors will jump ship. And look, the opposite could be true with Biden. If the media writes you off as dead and then you over-perform in Nevada or South Carolina and give a rip-roaring speech, the donors will come back. When I was with Obama, I always kind of knew in my gut how much we would raise based on the media narrative.”