Wednesday evening’s debate was a rousing, energetic, and highly entertaining kickoff to a crucial, high-stakes two-week stretch that will probably narrow the Democratic nomination contest to two or three contenders.

These are candidates who know it’s now or never. This Saturday, Nevada holds its caucuses. A week later comes the South Carolina primary. Just three days after that—10 days from today—it’s Super Tuesday, with roughly a third of all delegates in play.

As things now stand, Bernie Sanders figures to continue winning the same 25 percent or so that he took in Iowa and New Hampshire, and at which he is polling in Nevada and nationally. If the muddle behind him isn’t clarified quickly, the Vermont Senator will likely ride that 25 percent mini-wave to a Super Tuesday sweep, almost assuring him of entering the Democratic National Convention with the most delegates, if not the actual majority needed for the nomination.

So four candidates—Joe Biden, Pete Buttigieg, Amy Klobuchar, and Elizabeth Warren—must try, in these 10 days, to maneuver themselves to be the main challenger to Sanders.

Each has a case for it. Biden had been the national poll leader until recently; if he finishes second in Nevada and first in South Carolina, as polls still indicate, he roars into Super Tuesday. Buttigieg has a strong claim after running neck-and-neck with Sanders in both contests. Klobuchar has momentum after a strong third-place showing in New Hampshire. And Warren, despite a disappointing start, has the national popularity and organization to take advantage if she grabs the comeback kid mantle.

First, however, they had to swat back a late pretender to the title.

Dropping a deeply flawed, ill-prepared, and cartoonishly self-confident Michael Bloomberg onto the Democratic Presidential debate stage had its predictable result Wednesday evening: when the candidates weren’t taking turns burying their shivs in his flesh, they pretty much ignored him.

As it should be. Bloomberg’s appeal on paper—or more accurately, in carefully crafted thirty-second commercials and online ads—was always obvious, but so too were the gaping faults that will presumably prevent him from claiming the nomination.

It seemed almost frivolous, frankly, to bother skewering him this early, when he won’t even appear on the ballot in the next two contests. But, he was there, so skewer him they did.

With that out of the way, the four candidates revealed their paths to the anti-Sanders position by who else they went after, and how.

Buttigieg, for example, clearly believes he is poised to turn the race into a binary choice. So, he repeatedly took on Sanders, frequently turning to speak directly to him, as if to communicate to the audience that these are the two real combatants.

Buttigieg attacked Sanders almost from his first breath, warning that Sanders is too polarizing to win a general election. He chided Sanders for his bullying online supporters, his failure to disclose full medical records, and his expensive health care plan.

Biden’s plan is to continue projecting himself as the rightful heir, and so primarily stuck to asserting his bona fides while dismissing others as all talk. Klobuchar hopes to keep flashing the good-humored centrism that worked in the New Hampshire debate, although the spark didn’t seem to catch this time.

Warren’s Calculated Attacks

Warren’s approach seemed to confuse some viewers and commentators: she was firing lethal rounds in all directions, except toward Sanders. She even twice pivoted away from questions specifically about him, and at other times held her tongue at opportunities to strike.

She clearly wanted to avoid alienating Sanders supporters. In fact, she seemed to be trying to prove her mettle, to progressives who think Sanders might be too risky as a nominee, by smacking down the more centrist options with gusto.

Her epic assaults on Bloomberg, the “arrogant billionaire,” were just the beginning. Buttigieg’s health care plan is merely a slogan, she said, conjured by consultants and put onto Power Point—better, at least, than Klobuchar’s “Post-It note: insert plan here.”

But most telling was when Chuck Todd asked her how she differentiates herself from Sanders’s more anti-capitalist stances.

Without naming or explicitly criticizing him, Warren said that Democrats who want to beat Trump “are worried about gambling on a narrow vision… worried about gambling on a revolution that won’t bring along a majority of this country.”

She then quickly warned progressives not to let their search for electability lead them to a regretfully weak standard-bearer.

“Amy and Joe’s hearts are in the right place, but we can’t be so eager to be liked by Mitch McConnell that we forget how to fight the Republicans,” Warren said. As for Buttigieg, well, he “has been taking money from big donors and changing his positions, so it makes it unclear what it is he stands for.

That’s Warren’s case, in a nutshell, for being the not-Sanders candidate. It’s a bit of an odd, double-carom strategic-voting argument, but it seems that this year a lot of Democrats are stuck trying to game out their votes as though they’re confronting a Stratego board. They’ll need to make their move in these coming ten days.