Former Vice President Joe Biden reclaimed his status as a Democratic front-runner with stunning victories on Super Tuesday and opened a clear path to amassing enough delegates to clinch the nomination by the Democratic National Convention.

Sen. Bernie Sanders, the left wing’s champion, has dodged a knockout blow for now. While he has lost his lead in pledged delegates, he remains competitive and he has probably stopped Biden well short of an overall majority of delegates awarded on Super Tuesday.

But the results nonetheless leave reason to doubt whether Sanders can fare well enough to amass a majority of pledged delegates by the convention without yet another big turn in the race, this time in his favor. He was largely swept in the Eastern half of the country, where most of the delegates awarded after Super Tuesday are at stake. And in many states he was assisted by large numbers of early voters who cast ballots before the South Carolina race, when the party’s moderate voters were still divided. He will no longer have that advantage.

Biden swept the South with expected, overwhelming support among black voters, who backed him by a margin of 56% to 19% across the Super Tuesday states, according to exit polls. His success among white voters was less expected and allowed him to extend his strength well beyond the South.

He ran even or ahead among white voters in every state east of the Mississippi River, except for Sanders’ home state of Vermont, according to exit polls, and won decisive victories in the affluent suburbs around Boston, Washington and Minneapolis-St. Paul. He carried much of the older, moderate rural vote that Sanders swept four years earlier.

Biden rapidly consolidated moderate-leaning voters in the days after his landslide victory in the South Carolina primary. Pete Buttigieg, the former mayor of South Bend, Ind., and Sen. Amy Klobuchar of Minnesota left the race and endorsed him, with the result that he appeared to add nearly all their former supporters. His strength across the rural North and in affluent suburbs mirrored their strengths in the Iowa caucuses and New Hampshire primary.

In a telling indication of how quickly moderate voters had coalesced behind Biden, exit polls across the Super Tuesday states found that among voters who decided in just the last few days, Biden won by a margin of 48% to 21%.

Sanders denied Biden a more sweeping victory because of the West, where Sanders can count on his strengths among Latinos, liberals and younger, urban voters. The West also has the highest rate of early voting in the country, which helped blunt Biden’s surge.

Overall, Biden has only 45% of pledged delegates after Super Tuesday, while Sanders is expected to come in with around 39%. These tallies could change depending on the eventual result in California, but if they hold, Biden’s delegate lead would be far from irreversible. In fact, Sanders would need to defeat Biden by only 3 points in the remaining two-thirds of the country to overtake him.

A 3-point deficit is not a daunting handicap, certainly not when Biden was polling 20 points lower just a few days ago. But the Super Tuesday results do not augur well for Sanders’ odds of pulling it off.

Biden needs around 54% of the remaining delegates to claim a majority heading into the Democratic nomination, and his path to accomplishing this might be as simple as repeating the same outcome as Super Tuesday in a more favorable set of states, without the burden of early votes cast.