Tuesday, April 5, the people of Wisconsin vote, and what once appeared to be a clear victory for one Democratic candidate, now looks as if it will turn out exactly the opposite.

This time a week ago, polls showed former Secretary of State Hillary Clinton with a lead in Wisconsin ranging from 5 to 9 points, depending on which poll you consulted. Now, a mere four days before the first ballot is cast, three separate polls show Vermont Senator Bernie Sanders in the lead and well-positioned to take the lion’s share of 96 delegates at stake.

In a poll, released March 23 by Emerson College, Clinton held a six point lead over Sanders. That lead is gone. Another poll, conducted Wednesday by Marquette University, shows Sanders in the lead by four points.

Momentum appears to be on the side of the Sanders campaign, and it was announced today that the campaign had raised $44 million in March. Also, fresh off wins last week in Alaska, Hawaii, and Washington, the Vermont Senator continues to draw enormous crowds for his campaign rallies. Just yesterday, Sanders drew an estimated 18,000 enthusiastic supporters to a rally in South Bronx, New York.

All of this good news for the Sanders camp stands in contrast to what appears to be happening with the Clinton campaign. Though Clinton still leads in overall delegates 1,712 to 1,011, with another 2,042 not yet allocated, the trend is clearly towards Sanders. Can he continue this unprecedented comeback and overtake Clinton, who was once considered a virtual lock for the Democrats?

In recent weeks, Sanders has also been speculating aloud that should he continue to win and amass delegates, even if he doesn’t have more than Clinton when the Democratic convention is held in Philadelphia this July, he might be able to convince many superdelegates–of which Clinton has 469 and Sanders only 31–to pledge their loyalty to him because he feels he is building a “movement,” which makes him the more formidable candidate to face whoever the GOP winds up nominating.

Nate Silver of FiveThirtyEight says he cannot see how Sanders could manage to get another 988 delegates, which he would need to win outright. But, stranger things have happened before in American politics, and might just happen again.

Just a day after his wins in Alaska, Hawaii, and Washington, Sanders declared momentum was on his side:

This article was originally published by the same author at BipartisanReport.com.