Bernie Sanders breathed new life into his campaign this weekend with resounding wins in caucuses in Washington, Alaska, and Hawaii, and now some experts believe he has another major and potentially race-changing upset on the way in Wisconsin.

Sanders was in danger of falling out of contention entirely earlier this month, enduring a series of losses and watching Hillary Clinton seize the momentum of the race. But that changed with a shocking win in Michigan, where polls had showed Clinton with a 20-point lead leading up to the vote. Suddenly the Sanders campaign had new energy, which has been carried even further with a string of wins that have cut into her delegate lead.

To keep it going, Bernie Sanders has a tall task. The states that favor his voter demographic are winding down, and the schedule has a series of states coming up that polls — and experts — believe Clinton should win easily. He needs to win close to 58 percent of all delegates remaining to catch Clinton, which seems difficult given her 30-point advantage in polls for delegate-rich New York.

But Bernie Sanders could have another boost of momentum on the way. Just like his win in Michigan energized the campaign, a potential upset in Wisconsin could turn the race on its head and destroy the conventional wisdom about what states Hillary Clinton could and should win.

Hillary Clinton, Bernie Sanders shift focus to "pivotal" Wisconsin: A win for Sanders is… https://t.co/UZaNowno14 pic.twitter.com/reLJk1oJjC — Newsweek Europe (@NewsweekEurope) March 27, 2016

As Newsweek reported, there is a growing sentiment among political pollsters that Sanders could be primed for an upset in Wisconsin.

“On April 5, a less-predictable blend of voters in the maverick-friendly state of Wisconsin gets to have its say, and while Nate Silver may give Clinton an 84 percent chance at winning the primary, Sanders is every bit as likely to defy the polls in the Badger State as he was in Michigan, experts tell Newsweek. Sanders’s Michigan win was an important one because everyone can now point to it as evidence that the pundits and the polls are lying to you. If he wins in Wisconsin, that lends credence to the idea that Michigan was no fluke, and that Sanders belongs in the race.”

Sanders appears to have the enthusiasm on his side as well. This weekend he held a rally in Madison, Wisconsin, that drew thousands of supporters. In his speech, which coincided with his caucus victories, Bernie Sanders had an energized tone.

“Don’t let anyone tell you we can’t win the nomination, or win the general election,” he told the cheering crowd. “We’re going to do both of those things.”

Bernie Sanders has been making the case that he will be the strongest candidate to face Donald Trump in November, a pitch that The New Yorker noted could be gaining some traction.

“To win the nomination, Sanders needs to record some big upsets in the Northeast, then rack up victories by large margins in Western states like Oregon, Wyoming, and California, whose primary isn’t until June 7th. After Saturday’s results, the second part of that scenario doesn’t seem wholly outlandish. In his speech afterward, Sanders pointed to a recent poll from Bloomberg that showed him running slightly ahead of Clinton nationwide. And, according to the Huffington Post’s poll-of-polls, he is within striking distance in California.”

While a win in Wisconsin would give a boost to the campaign, a loss could essentially mean the end for Bernie Sanders. And with Hillary Clinton investing much time and money in the Badger State, it will certainly not be an easy run for Sanders the way his western swing was this weekend.

[Picture by Ralph Freso/Getty Images]