After his decisive victory in Wisconsin Tuesday night, Ted Cruz told supporters that the contest marked a "turning point" in the 2016 Republican primary race.

"Tonight is a turning point. It is rallying cry," he said from Milwaukee. "It is a call from the hard working men and women of Wisconsin to the people of America. We have a choice. A real choice."

Bernie Sanders had a similar night, defeating his Democratic primary opponent Hillary Clinton in the Wisconsin Democratic primary by more than 10 points.

Ted Cruz delivers his victory speech, with his wife Heidi Cruz by his side, after decisively winning the Wisconsin Republican primary.

"Let me say a word, maybe two, about what momentum is all about," Sanders said Tuesday night. "With our victory tonight we have now won seven out of eight of the last contests. And we have won almost all of them with overwhelming, landslide numbers."

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Yet for both candidates, the momentum they've earned in the Badger State may not be enough to get them through the uphill climb ahead.

A rough month ahead for Ted Cruz

For Cruz, creating a "turning point" in the race will take more than convincing voters in the remaining primaries to support him. With a series of challenging contests ahead of him in the coming weeks, Cruz will have to convince donors to keep funding his campaign. He'll have to convince party operatives to coalesce behind him and support him -- in just the way that Gov. Scott Walker, talk radio hosts and other key conservatives did in Wisconsin.

Meanwhile, he'll have to contend with Donald Trump's always-unpredictable campaign.

After his loss Tuesday night, the Trump campaign released a blistering statement, calling Cruz "a Trojan horse, being used by the party bosses attempting to steal the nomination from Mr. Trump."

Trump's eyebrow-raising statements -- about everything from nuclear war to members of his own party -- may finally be taking a toll on his image among Republican voters. The CBS News exit polling showed that Trump did not perform as well in Wisconsin among groups of voters who have backed him in previous primaries. For instance, Cruz won among those with college degrees but also among those without. The senator performed well among those who said they are "very conservative" as he has in previous primaries, but he also edges out Trump among those who said they are "somewhat conservative" -- a group that typically favors Trump.

On top of all that, more than one third of GOP voters said they are scared of the prospect of a Trump presidency.

It's possible this sentiment may be unique to Wisconsin. And given Trump's double-digit leads in New York and Pennsylvania -- where the 2016 race heads next -- his campaign will vigorously make that case. At the same time, Trump is clearly interested in recalibrating his campaign to appear more presidential. The Trump campaign told the Washington Post on Tuesday that the front-runner will make a shift in tone in the coming weeks, moving from style to more substance with a series of policy speeches.

If the front-runner can appear more presidential -- or at least avoid the sort of statements that may concern conservative voters, such as his muddled remarks about abortion -- he may be able to stay on track to keep the lead in the delegate race.

While New York and Pennsylvania are more favorable ground for Trump, Cruz could continue to accumulate delegates if he zeroes in on friendly congressional districts in those states.

Meanwhile, Ohio Gov. John Kasich's campaign is staying on message, arguing that no GOP candidate will win the 1,237 delegates needed to clinch the nomination. In a memo released Tuesday night, Kasich camp strategist John Weaver once again cited polls showing Kasich beating Hillary Clinton in general election match-ups. He also suggests that Kasich is Trump's main competition in the southern New England and mid-Atlantic states that vote next.

Whatever the Kasich campaign may argue, the governor's performance in Wisconsin raises even more questions about his long-shot campaign. He won just 14 percent of the vote, even though Rust Belt states similar to his home state of Ohio should theoretically be friendly territory for him.

Sanders' shrinks his delegate deficit, but not by much

With a victory in Wisconsin, Sanders picked up the burst of momentum he needed to continue making the case for his candidacy, in spite of Clinton's large delegate lead.

Democratic presidential candidate Sen. Bernie Sanders, I-Vt., gestures to supporters during a campaign rally in Laramie, Wyo., Tuesday, April 5, 2016. Brennan Linsley, AP

Exit polling from the state shows that Wisconsin's electorate played exactly to Sanders' strengths from previous contests. He was aided, for example, by a particularly massive margin among young voters in the primary. Among those aged 18 to 29, Sanders led Clinton by a 64-point margin (81 percent to 17 percent). Clinton, meanwhile, won voters aged 45 to 64 by a 9-point margin (54 percent to 45 percent) and voters over 65 by a 22-point margin (60 percent to 38 percent).

The Vermont senator also won among white voters, who made up 84 percent of the Wisconsin Democratic electorate, by an 18-point margin (58 percent to 40 percent). Clinton won among African Americans as she usually does--and by 48 points--but African American voters were just 9 percent of the overall Democratic electorate on Tuesday.

Self-described liberals, too, who made up 66 percent of the electorate in Tuesday's Democratic primary, backed Sanders by a 17-point margin. He won among moderates, too, but by just one point -- 50 percent to Clinton's 49 percent.

Sanders also fared especially well among independents, who made up more than a quarter of the Democratic primary electorate. Seventy-one percent of self-described independents supported him, compared with 28 percent who backed Clinton.

Sanders has depended on open primaries to notch many of his victories thus far; however, only a few remaining states have open primaries in which independents are eligible to vote, which will pose a challenge for him going forward.

What's more, Sanders put significant resources into the state--making it clear how much of a priority it was for his team. He outspent Clinton by almost $1 million on television and radio, spending $2.4 million to her $1.43 million there since March 22.

Thanks to his strong fundraising, Sanders can continue to vigorously campaign. Even so, he'll have to win by wide margins if he wants to catch up to Clinton in the delegate race, given that Democratic delegates are awarded proportionally.