Here's how important one of the nation's wealthiest conservative political action committees thinks Wisconsin's primary could be to the GOP nomination battle:
"Wisconsin is really crucial at this point. It stands alone. It's a significant number of delegates and, in a sense, it could be a tide-turner."
The speaker is Doug Sachtleben, spokesperson for Club for Growth. Never before has his PAC endorsed a presidential candidate. But Club for Growth has gone all-in with its support for Texas Sen. Ted Cruz, bombarding the Badger State with $1 million worth of TV ads.
Well-known Republicans have joined forces in hopes of defeating Donald Trump in Wisconsin's GOP primary Tuesday. From Gov. Scott Walker on down, the message is that Cruz is the only viable conservative in the race. In a current commercial, Walker calls Cruz "the only conservative who can beat Hillary Clinton and reignite America's promise."
Sachtleben called Trump unacceptable as a Republican presidential candidate, in part because he supports single-payer health care and tax increases.
Trump's campaign did not respond to MPR News inquiries about the Wisconsin primary.
Sachtleben said if Wisconsin stops Trump, the chance of Republicans denying him the GOP nomination this summer greatly increase.
"We feel like Wisconsin is very pivotal," he said. "I don't want to say that if Trump were to win, there's kind of a media narrative that it's almost over anyway, and we're not ready to buy into that because you have still got, I think, 16 states after Wisconsin. Nonetheless, there's no discounting the fact that there's a lot at stake in Wisconsin and that's why we're putting the effort in there."
A Marquette Law School poll released last week showed Trump has lost his lead among likely Wisconsin GOP primary voters. Cruz is now 10 percentage points ahead of him. But, according to the poll, Trump and Cruz are running neck-and-neck in northern and western Wisconsin.
Even if Trump loses statewide, he could pick up delegates regionally. More than half of Wisconsin's delegates are awarded by congressional district.
Wisconsin State Assemblyman Dean Knudson represents areas of western Wisconsin including Hudson, where Cruz opened a campaign office late last week. Knudson, a co-chair of Cruz's Wisconsin campaign, said there's a big push to get out the vote for Cruz.
"We've got people that are out knocking on doors. We've got people that are calling voters, finding undecided voters, encouraging voters to get out and vote," he said.
Political strategist Mark Graul said Trump does not appear to have much of an organization in Wisconsin, compared to what Cruz has put together. He added that Trump's behavior is costing him votes in the state.
"Wisconsinites, like most of the country, have heard lots about Donald Trump over the last many months, and I think in Wisconsin, we consider ourselves to be pretty polite, nice people," he said. "And I don't think Donald Trump's brand of anger and vulgarity in campaigning is selling all that well in our state."
In a cigar shop in downtown Hudson, 59-year-old Lon Feia voiced a different view. He's supporting Trump and is unhappy with the establishment effort to undermine him.
"Frankly, as a lifelong Republican, I'm disgusted by the whole process," he said. "What we see here with Trump, in my opinion, is a clear rejection of politics as it's been. People love him. Why? Because he calls a spade a spade. And he is definitely the anti-politician, and I feel that their continual attacks are having an effect."
Many Democrats think Trump would be the easiest Republican to defeat this fall. That's why some have have crossed over and supported him in other states. Graul said he doesn't expect crossover to be a major factor in Wisconsin, where the close contest between Bernie Sanders and Hillary Clinton likely will motivate Democrats to vote in their own primary.