Aaron P. Bernstein / Reuters

Assuming Indiana voters don’t shock the pollsters tomorrow, Donald Trump will win the Hoosier State, and with that win all-but-clinch the Republican nomination for president.

How did things get here? Cruz was always a long shot for the nomination, but as the field cleared and it became clear that the Texan was the only viable alternative to Trump, states like Indiana were expected to be a firewall, preventing Trump from reaching the majority of delegates required to capture the nomination on the Republican National Convention’s first ballot. Instead, Cruz goes into Tuesday’s primary a deep underdog. The last poll, from NBC, The Wall Street Journal, and Marist, even had Trump up 15 points, though most show a slightly closer race.

Maybe momentum really is real, and Trump’s riding the wave of his huge wins in the Northeast a week ago. Maybe the visceral loathing of Cruz from his fellow Republicans finally caught up with him. Maybe that “basketball ring” gaffe was lethal. But Indiana is supposed to be the sort of state where Cruz would shine.

The state is heavily white. It’s just about average in terms of conservatism overall, but the state has recently tended to elect, and the Republican Party to nominate, leaders who are Tea Party oriented and deeply socially conservative, from Governor Mike Pence to unsuccessful 2012 Senate nominee Richard Mourdock. More than a quarter (26 percent) of Indianans identified as white evangelical protestants, according to the Public Religion Research Institute’s American Values Atlas. That’s the ninth-highest concentration of evangelicals nationwide, and almost nine points higher than the national average of 17.3 percent. In the 2012 election, exit polls recorded that fully 35 percent of Indiana voters identified as white, born-again Christians.

One story of the Cruz campaign is the senator’s failure to win states just like this. Once upon a time, such states were going to secure the nomination for Cruz—the slate of conservative, religious Southern states voting in the March 1 “SEC Primary” was going to stop Donald Trump and vault Cruz ahead. Instead, Cruz won his home state of Texas, along with Oklahoma and Alaska, but lost to Trump in Virginia, Arkansas, Tennessee, Alabama, and Georgia. In those states, the twice-divorced New York billionaire won a plurality of evangelicals, beating Cruz among the very voters expected to make up his base.

The polling in Indiana isn’t the only warning sign for Cruz. Over the weekend, the Tampa Bay Times noted comments by Senator Marco Rubio that suggest he might be “warming up to Donald Trump.” The New York Times and National Review both published stories on Sunday about how some of the delegates whom Cruz had so effectively managed to place on slates around the country—with the intention of capturing them on a second ballot at the convention—were starting to waver as Trump’s lead grew, and opening up to the idea of voting for Trump.

But if Cruz loses Indiana, it will show how the delegate-selection circus really was a sideshow. Cruz has been hobbled all along by his failure to win evangelical-rich states, so it would be fitting if Trump manages to deal his campaign a mortal blow by beating him in just such a state on Tuesday.

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