Ted Cruz and Bernie Sanders upended their respective parties' front-runners with big wins in the Wisconsin primary Tuesday.

Cruz's victory over Donald Trump is an important step toward denying the real estate developer the delegates he needs to win on the first ballot at the Republican National Convention. Meanwhile, Sanders is extending a win streak that will keep the Democratic race going even though Hillary Clinton has posted a formidable delegate lead.

The vote comes as Trump has experienced the worst two weeks of his campaign, with falling general election poll numbers, a series of well publicized gaffes and his campaign manager being charged with simple battery.

"As a result of tonight, as a result of the people of Wisconsin defying the media, defying the pundits, I am more and more convinced that our campaign is going to earn the 1,237 delegates that's needed to win the Republican nomination," Cruz said. "Either before Cleveland or at the convention in Cleveland, together we will win a majority of the delegates and together we will beat Hillary Clinton in November."

Cruz jumped out to a lead in most Wisconsin polls, including the widely respected Marquette Law School survey, although this week has seen some tightening. Gov. Scott Walker, a former 2016 contender himself, and nearly the entire state Republican leadership structure have embraced Cruz's candidacy.

Wisconsin conservative talk radio was less sympathetic to Trump than in other parts of the country, with local host Charlie Sykes having a contentious interview with the Republican front-runner. House Speaker Paul Ryan has been a thinly veiled area Trump critic as well, though he hasn't endorsed in the primary.

Cruz hopes his win in Wisconsin will help change the narrative that Trump's delegate lead is nearly insurmountable and may even weaken the billionaire's grip on the Northeastern states voting next. The Texas senator needed to change something fundamental in the race after mainly beating Trump in caucuses and smaller delegate hunts where he can out-organize the political neophyte.

The slower pace of the primary calendar at this phase of the race may be damaging Trump's ability to limit the effect of controversies by turning the page as each new state holds a primary or caucus.

The Badger State primary loss comes as amidst reports that Trump is reshuffling demoralized and will roll out a series of policy speeches to convince Americans he can be presidential. Most voters told exit pollsters they were scared or concerned about a Trump presidency.

On the Democratic side, Clinton continued to struggle with voters looking for a candidate who is honest and trustworthy, the candidate quality that mattered most to a plurality of Wisconsin Democrats. She lost unmarried women and younger voters in a landslide that saw Sanders take 82 percent of the millennial vote.

"With our victory tonight in Wisconsin, we have now won seven out of eight of the last caucuses and primaries and we have won almost all of them with overwhelming landslide numbers," Sanders declared from Wyoming.

Cruz called Wisconsin a "turning point" in the Republican race. The question for both senators is whether Tuesday night turned anything around or whether the front-runners will reassert themselves with big wins in New York two weeks from now.

The answer may be different for each man. While Sanders has been beating Clinton lately, Michigan has been his biggest victory in a state with a significant black vote. He is cutting into Clinton's lead among pledged delegates but he is not at risk of overtaking her. Factor in superdelegates and the math becomes even more challenging.

Cruz's Wisconsin win comes at a time when Trump's position in the general election is deteoriating and the billionaire's standing with Republican voters appears to be plateauing. Unbound delegates actually help Cruz in his quest to keep Trump from clinching the nomination and he has been doing well at the state conventions where many of those delegates were chosen.

For Cruz, it had to be gratifying to listen to the crowd chant his wife's name during his victory speech. Even if Wisconsin wasn't a turning point, Trump's gleeful retweeting of an unflattering image of Heidi Cruz may have been one with women voters. The Texan beat Trump by 13 points among women who voted in the GOP primary in Wisconsin.

Clinton and Sanders next meet in Wyoming, but Cruz and Trump don't face off again until New York on April 19.