• Wisconsin provides a clear test about Trump’s durability following arrest of his campaign manager, falling popularity, attacks on Cruz’ wife, and outlandish statements on abortion
• An average of polls gives an edge to Ted Cruz, and the most recent one by a whopping 10 points
• Provides the best opportunity for anti-Trump crowd before primaries shift to Northeast, where Trump has enjoyed strong support

Donald Trump famously said he could shoot someone in the middle of New York City’s bustling Fifth Avenue and not lose voters. It was a boast meant to underscore the unshakable nature of his support among a plurality of Republican primary-goers, and it caught attention for more than its bombast. It may have been an obvious exaggeration, but its basic point and effect felt true. This man’s support has truly seemed impervious to reason, fact, convention, or what actually happens in this place we previously took for granted as a living world of sentient beings.

In the face of another string of scandals and signs of even greater backlash against Trump, next week’s vote in the Wisconsin primary provides perhaps the clearest test yet of Trump’s I-could-shoot-someone durability. And the polls in this important Midwestern battleground show a loss is entirely possible.

But the question is whether a loss in Wisconsin would carry into the populous Northeast, where Trump has done well with the region’s less ideologically pure brand of conservatism. His appeal in the Northeast – and the fact that the next six contests are on Trump-friendly terrain – makes Wisconsin an important station on the Stop-Trump Express.

What could bring Trump down?

Sure, Trump stalwarts are likely to take his side in the latest scandals, but they’re going to guarantee anyone who was on the fence will vote for someone else, and he can’t afford to continue alienating everyone who isn’t already lining up to attend his rallies.

His campaign manager, Corey Lewandowski, was charged in Florida with battery on Tuesday after grabbing a reporter on the arm earlier in March after she approached Trump to ask a question. The incident was captured on video, which cleary shows Lewandowski grab her arm but is less conclusive about the severity of the incident.

But the reporter, Michelle Fields of conservative outlet Breitbart News, produced photos of bruises, has some additional audio evidence of her own and other witnesses. Trump stalwarts are sure to take his side, but that’s not the point – he needs to expand his support to get to a majority of primary delegates, and instead of quickly dispatching Lewandowski he’s coming to his aide and blaming the victim, further souring his already anemic support with women.

Next up is Trump’s latest tiff with Ted Cruz. He’s threatened to “spill the beans” on Cruz’ wife in retaliation for criticism of Trump’s own wife from a group that supports – but is not funded by or works directly for – Cruz. Even Newt Gingrich, that beacon of decency, has questioned the wisdom behind this latest foray.

On top of all that, Trump had a disasterous interview with a popular and influential Wisconsin radio personality who’s personally calling for voters to support Cruz. And, as a final touch, Trump said women seeking abortions should be “punished” — an idea that even the most ardent anti-abortion advocates call beyond the pale.

What the polls are saying

The bigger problem with these latest developments: they’re coming up as Trump’s popularity – never actually that good to begin with – is cratering. An average of recent polls from the Huffington Post give Trump an average favorability of only 31 percent, which is down from 37 percent as recently as February. Perhaps more worrying is Trump’s standing with independent voters, which stands at a net- negative of 27 percent. Those independents, who make up about 20 percent of the Wisconsin electorate, could well be decisive in this winner-take-all race that is coming down to the wire.

A Real Clear Politics average of Wisconsin polling puts Cruz up by three points, but the most recent one gives him a 10-point edge over Trump.  That could be a sign that Wisconsin voters have been listening, and they don’t like what they’re hearing. Regardless, the race looks to be close, and Trump isn’t doing himself any favors.

Losing a contest that awards all 42 delegates to whoever wins the largest share of voters would be a big blow, given that Trump needs to win more than 50 percent of the remaining 943 remaining delegates to clinch the nomination.

What will it mean if Trump loses?

This is a difficult question to prognosticate. What’s indisputable is that every time Trump loses it makes it harder to reach a majority, and if he doesn’t reach a majority there’s a good chance Republican Party leaders will engineer an effort to deny him the nomination. The problem is that, after Wisconsin, the race turns to the Northeast and Mid-Atlantic, and so far Trump has performed quite well in the Northeast.

New York, with its huge delegate count of 95, is up for grabs first, and Trump is dominating in the polls there. Then come neighboring Connecticut, Delaware, Maryland, Pennsylvania, and Rhode Island. Trump looks good, though less invulnerable, in some of those other states as well. In fact, Trump likely benefits from Ted Cruz’s repellence to East Coasters, who can’t stomach his firebrand conservatism. But John Kasich simply hasn’t emerged as a true alternative to fill in the gaps there.

In the end, Wisconsin might not matter, but it’s a contest Trump could well lose, and it helps the Never Trump crowd deny him a party christening in July. And a win for Cruz significantly helps him make a case that he can beat Trump in larger, more diverse and less stridently conservative states. Cruz will need that going into the Northeast.