Troubling incidents in the past two months helped turn Wisconsin into the most important primary of the year. Photograph by Jabin Botsford/The Washington Post via Getty

Late March and early April represent a kind of cooling-off period in the Presidential-nominating calendar. From February 1st through March 15th, thirty-five states and territories participated in Republican primaries and caucuses. That six-week blast of voting reduced the field of Republican candidates from twelve to three, and produced a front-runner, Donald Trump, whose sixty-three-per-cent unfavorability rating makes him one of the most unpopular politicians in America.

After that frantic period of voting, the race slowed considerably, with only four states holding Republican contests during the following month: Arizona and Utah (on March 22nd), Wisconsin (last night), and Colorado (this Friday). Donald Trump could have used this spring pause to establish his dominance in the race. There were signs that important establishment figures, such as Bob Dole and Newt Gingrich, were accommodating themselves to his candidacy. Trump could have used G.O.P. hatred of Ted Cruz to woo Party regulars and Republicans in Congress. He could have delivered a series of policy speeches to prove that he has even an elementary understanding of major issues.

In March, there were two signs that Trump was attempting this sort of pivot. At the last Republican debate, on the 10th, he declined, for the most part, to act boorish and immature, and behaved in a way that many pundits described—using an admittedly very low bar—as “Presidential.” Then, on the 21st, Trump delivered a traditional speech to the American Israel Public Affairs Committee, in which he overtly pandered to the pro-Israel interest group—evidence, whatever one’s views about the Middle East, that Trump can occasionally respond in a rational way to political currents.

But the debate and the AIPAC speech were exceptions, drowned out by a series of troubling incidents throughout March and April that helped turn Wisconsin into the most important primary of the year. First was Trump’s baffling refusal to disavow an endorsement from David Duke, the former Grand Wizard of the Ku Klux Klan, during an interview with Jake Tapper, on February 28th. Reviewing Trump’s position in head-to-head polls against Hillary Clinton, it seems this may have been an important event: Hillary Clinton’s lead over Trump grew from three to eleven points in the following month.

That widening gap was likely aided by what came next. After the K.K.K. imbroglio, there was a weeks-long discussion about violence at Trump’s rallies. Trump personally encouraged his supporters to physically engage with protesters on several occasions; not surprisingly, a few of them followed his advice. Somewhat surprisingly, his own campaign manager, Corey Lewandowski, was one of them. On one occasion, Lewandowski grabbed a protester by the collar. On another occasion, he grabbed a female journalist so hard, allegedly, that he bruised her arm, apparently to prevent her from asking Trump a question. (Lewandowski faces a simple-battery charge over the incident; he has denied the charges.) In its initial response to both incidents, the Trump campaign gave out information that was simply false, insisting that Lewandowski never touched either the protester or the reporter.

Meanwhile, rather than use this sleepy period in the campaign to attempt to show that he has some command of the issues, Trump continued to grant long interviews that exposed a shocking lack of familiarity with even basic policy questions. In one, Trump managed to horrify the editorial board of the Washington Post with incoherent answers and “breezy willingness to ignore facts and evidence,” as well as with his casual sexism.

A rational candidate would at least try to mitigate the damage that his well-deserved reputation for misogyny has done. Instead, Trump spent March repeatedly attacking Megyn Kelly, the most popular female journalist in the conservative media, and, in one of the more reprehensible moments of a very low campaign, he tweeted an unflattering picture of Ted Cruz’s wife and threatened to “spill the beans” on her (whatever that means). That controversy was soon eclipsed by Trump’s multiple, contradictory responses when asked what he believed about abortion. In the course of three days, he ricocheted from arguing that abortion should be illegal and that women who undergo the procedure should face punishment to essentially arguing that abortion laws should remain unchanged.

In the Arizona and Utah contests, held after some but not all of these events, there was a split verdict on Trump. He won Arizona, where his harsh anti-immigration message is popular among Republicans, and lost Utah, where Mormons acted like the Republican Party’s designated drivers by resoundingly rejecting Trump. Utah allowed the anti-Trump movement a brief respite: the race may have been over had Trump won there.

Wisconsin then became the crucial test of whether Trump could truly get away with anything. As with Utah, if he had won Tuesday’s primary in Wisconsin, after all that has happened in the past few weeks, he would almost certainly become the Republican nominee for President. But Cruz won, forty-eight to thirty-five per cent. The exit-poll results suggested that voters were motivated more by disgust with Trump than by enthusiasm for Cruz. Fifty-eight per cent of Wisconsin voters said that they would be “concerned” or “scared” if Trump were elected President, and sixty per cent of Cruz voters said that they would support a third-party candidate in the general election over Trump if Trump were the Republican nominee. (The feeling is mutual: seventy-one per cent of Trump voters said that they’d support a third-party candidate over Cruz.)

Donald Trump has famously said that he could shoot someone on Fifth Avenue and his supporters wouldn’t abandon him. That may still be true. His base is incredibly loyal. But it’s also relatively small: Trump has won only thirty-seven per cent of the popular vote in the thirty-five states and territories that have held Republican Presidential-nominating contests in 2016. Put another away, almost two-thirds of Republicans are anti-Trump. The March and April interregnum was Trump’s great opportunity to win over that large majority of Republican holdouts and show that he has a second act. He blew it. Mathematically, Trump’s loss in Wisconsin makes it much more likely that he will fail to win the 1,237 delegates necessary to win the Republican nomination, on the first ballot, at the convention in Cleveland in July. Wisconsinites have handed the Republican Party a gift. Thanks to them, with a major assist from Utahans, Republicans may still save themselves from nominating the most unpopular man in America.