In politics, timing is everything.

That’s what former Vice President Joe Biden seemed to learn Tuesday, when after weeks of failure on the campaign trail, a great few days turned into a tide-changing wave of victories.

Going into Tuesday night, when 14 states and American Samoa picked their preferred Democratic presidential contender, polls suggested Biden was doing well in the South and that Sen. Bernie Sanders (I-VT) was positioned to win everywhere else.

Instead, Biden won Minnesota. He won Massachusetts, in Sanders’ backyard. And at press time, he had a shot at winning Maine, too. Texas, which previously seemed within Sanders’ reach, was up in the air. Even in California, Sanders’ delegate-rich stronghold, Biden was putting points on the board.

That’s on top of a landslide Biden victory in Virginia — where Biden, not Sanders, fueled a turnout record — and strong showings all over the South. High turnout from African Americans, older voters and suburban districts fueled the charge.

“The race has crystalized, after South Carolina, into a two-person race,” said Joel Benenson, a pollster who worked on Barack Obama and Hillary Clinton’s presidential campaigns, and who worked this cycle with former South Bend mayor Pete Buttigieg. Buttigieg, along with Sen. Amy Klobuchar (D-MN), endorsed Biden Monday night, hours before Tuesday’s voting began.

Biden appeared to be riding a wave. Exit polling showed that voters who decided in the past few days broke roughly two-to-one for Biden against Sanders, even in states in which Biden had a tiny campaign footprint.

“Joe Biden did not win because of television spending,” said Sean McElwee, executive director of the progressive polling firm Data for Progress. “He did not win because of a ground game. He didn’t win because he had lots of field offices. He didn’t win because his digital ads worked.”

“He won because of a very strong earned media presence and the endorsements of lots of very high-profile politicians.”

Appearing in front of cheering supporters a few minutes after 10 p.m., Biden practically yelled, “It’s a good night! And it seems to be getting even better!”

In the weeks leading up to Tuesday and after a split decision in Iowa, Sanders won New Hampshire outright and Nevada in a landslide. But Biden then trounced Sanders Saturday in South Carolina.

It was possible Biden could have fizzled Tuesday night, paving the way for Sanders’ nomination. But his victory in The Palmetto State seemed to signal a change in the tide.

His strong showing Tuesday even in states where he wasn’t projected to win foretells a much longer fight for the Democratic nomination. It didn’t hurt that Biden and Sanders’ second-tier competitors, Sen. Elizabeth Warren (D-MA) and former New York Mayor Mike Bloomberg, performed poorly across the board on Super Tuesday. Warren’s campaign suggested it would keep chugging along; Bloomberg will reportedly reassess.

“I think the most worrying thing if you’re Sanders is Biden’s performance in states like Maine, Massachusetts, Minnesota,” McElwee said. “This means he’s creating a pretty broad coalition this cycle.”

Benenson concurred, “You’re seeing some surprises in Bernie Sanders’ backyard.”

Sanders, once the lone frontrunner in a crowded Democratic field, now faces essentially a head-to-head match with the popular former vice president. And, McElwee noted, Biden still stands to win big in soon-to-vote states like Mississippi, Georgia, Louisiana, and elsewhere around the country.

Sanders, determined as always, emphasized the long game to his supporters Tuesday night.

“It’s a funny thing,” he said. “Thirty-one years ago today, we won the mayoral race in Burlington, Vermont. And we won that race against all of the odds. Everybody said it couldn’t be done. And when we began this race for the presidency, everybody said it couldn’t be done. Tonight, I tell you with absolutely confidence, we’re going to win the Democratic nomination.”