Bernie Sanders promises a political revolution, and on Tuesday he dramatically upended expectations, beating Hillary Clinton in Michigan.

Sanders’s tight victory surprised nearly everyone—including the Sanders campaign. The candidate spoke early in the night, then reemerged for a hastily arranged statement as the late returns suggested he was headed to victory. By the time the race was called, after 11 p.m., he had gone to bed. Nate Silver described the win as “among the greatest polling errors in primary history.” In practice, the win won’t provide a huge cache of delegates to Sanders, who trails Clinton, thanks to proportional representation rules.

But the win offers Sanders new momentum, along with two promising indicators. First, he was able to cut into Clinton’s consistent edge with black voters. Exit polls suggested Sanders won three in 10 African Americans in Michigan, his best showing so far. Second, it offers evidence that his message of fighting for blue-collar workers and opposing free-trade deals can resonate—and with Ohio and Illinois coming up on the primary calendar on March 15, he’ll soon have the opportunity to employ that message again.

It’s too early to tell why expectations were so far off in Michigan, and why the polls missed by so much. As polling places closed, the Clinton campaign hastened to depress expectations. One potential culprit is Clinton’s late attack on Sanders, in which she alleged that he had opposed the rescue of the car industry, because he had voted against bank-bailout bills that included funds for automakers. The attack seemed implausible on its face, much like Clinton’s earlier attempt to convince voters that Sanders wanted to eliminate Obamacare. But that charge might have been as much a symptom of Sanders’s gains—a last-ditch hit launched by the Clinton campaign as her edge dwindled in internal polls—as it was their cause. Sanders also benefited from his appeal to independents, who are permitted to vote in Michigan’s Democratic primary. Some reporters speculated that Clinton was also hurt by voters who crossed over to vote Republican, thinking she had the race locked up.

“I want to thank the people of Michigan who repudiated the polls [and] who repudiated the pundits,” Sanders said in his late-night comments. “What tonight means is that the Bernie Sanders campaign, the people’s revolution that we are talking about, the political revolution that we are talking about, is strong in every part of the country, and frankly we believe that our strongest parts are yet to come.”

Sanders’s upset is all the more interesting because the rest of the evening played out pretty much exactly as expected. In Mississippi, Clinton easily defeated Sanders. On the Republican side, Donald Trump cruised to victory in Michigan, Mississippi, and Hawaii. Ted Cruz won in Idaho.

In short, Trump is back—if he ever left. After underperforming high expectations on Saturday, he rebounded on Tuesday. In Mississippi, he neared the 50 percent mark, with Ted Cruz trailing around 10 points back. In Michigan, Trump was headed toward more than a third of the vote, with Cruz and John Kasich fighting for second place in a tight race. For Cruz, the Mississippi result is a disappointment. Once again, Trump, the thrice-married, prevaricating loudmouth from New York, beat him in the South and won most evangelical voters (taking 48 percent, according to exit polls)—stealing both the region and the demographic that were supposed to lift Cruz. The Texan remains the consensus alternative to Trump, though. Kasich, meanwhile, had campaigned hard in Michigan, betting that its proximity and similarity to his home state of Ohio would lift him. The March 15 primary in the Buckeye State is a must-win and could be his last stand.

But Marco Rubio was the night’s biggest loser. The Florida senator failed to cross the 15 percent threshold required to win a share of the delegates in either Mississippi or Michigan. He didn’t even clear 10 percent. Those poor showings come on the heels of a nearly as dismal March 5 performance, mitigated only by his win in Puerto Rico on March 6. It’s a catastrophic moment for Rubio, who once seemed to have a bright future in the Republican Party, and who had won the affection of the party’s establishment. It’s clear now how little that counts for this year. Ordinarily, Rubio might face calls to drop out of the race now, but with his home-state Florida primary approaching on March 15, he might just hang until then. He’s promised to win the Sunshine State, but few analysts or polls give him a strong chance.

On stage at a rally there Tuesday, Rubio touted the Florida Gators and joked, “It’s friendly territory, I hope,” then added—less jocularly—“Look, I need everyone’s votes right now. I can’t lose anyone’s votes.” Rubio, his voice hoarse from campaigning, told the crowd, “I believe with all my heart that the winner of the Florida primary next Tuesday will be the nominee of the Republican Party.” He may be right, but the odds that nominee will be him look very thin.

Trump was also in Florida Tuesday evening, at his Jupiter golf club near Palm Beach, where he delivered a characteristically bizarre victory speech and press conference. He hailed retired Yankees outfielder Paul O’Neill, who was in the audience, and his endorser Governor Chris Christie of New Jersey, who was not, although Trump said he was. Trump promised he “could be more presidential than anyone, except the great Abe Lincoln.” He alternatingly taunted and mocked Cruz, Mitt Romney, and all the other people who had rallied around the #NeverTrump cause.

“There has never been spent more money hitting somebody than has been spent on me ... Advertising is not as important as competence,” he sniped, and then proceeded to debunk his own point by delivering a lengthy spiel—the whole thing carried live on national television, of course—advertising many of the products in his stable, from the Jupiter resort to his branded vodka to his hotels to his steaks. The last line got special attention: Trump Steaks were largely discontinued years ago, and while there were alleged specimens at the event, closer inspection showed they were purchased from a Palm Beach butcher. (Placing his name on things he didn’t build is, of course, a signature Trump real-estate technique.) Early in Trump’s campaign, his bid was derided as just a publicity ploy for his business empire; now, with the nomination within reach, he appears to be fully embracing that role. Reporters asked a few questions, but none focused on the questionable business dealings and associations that have emerged in the last few days.

Trump is right about at least one thing: “We have something special going on in the Republican Party.” He seemed set to lock up more than 40 delegates and add to his lead. With a comparably resounding win on March 15, taking Ohio and Florida, Trump could put the race nearly out of reach. Or he could stumble once more, and again give his rivals a chance to deny him the 1,237 delegates he needs to avoid a contested convention.

On the Democratic side, Sanders’s victory is more moral than material. Because Michigan’s delegates will split proportionally, Clinton will end up taking significantly more delegates on the night than Sanders, adding to her already sizeable lead. (Due to the arcana of delegate-allocation rules, she might even end up with more Michigan delegates.) But winning Michigan breathes new life into Sanders’s campaign: It helps feed his money machine, and it raises hopes that he is learning how to reach black voters—or that he can reach black voters in the North in a way he couldn’t in the South. For Clinton, the moral blow is similarly large. She’s been speaking about Flint’s lead crisis for months, going out of her way to mention it in debates and presenting herself as the protector of the state’s most vulnerable. In retrospect, however, it seems obvious that with its scars of deindustrialization, Michigan would be prime territory for Sanders.

Now both parties look ahead to March 15, with its contests in Florida, Ohio, Missouri, North Carolina, and Illinois. For the Democrats, it offers a mix of demographic and geographic profiles. Several of those states are winner-take-all for the Republicans, and they could either give Trump a chance to put the race out of reach or for Cruz to gain significantly.

—David Graham