The Slatest

What I’ll Be Watching for at Tonight’s Iowa GOP Caucus

Donald Trump speaks during a rally at the airport on Jan. 30, 2016, in Dubuque, Iowa.

Scott Olson/Getty Images

The Republican nominating contest officially kicks off in Iowa tonight. The caucus won’t decide the GOP nomination, but it will start to make sense of what has been a chaotic and confusing campaign that has forced politicos and pundits, including yours truly, to question everything they thought they knew about modern politics. Are Donald Trump’s polling numbers a media-fueled mirage? Is Ted Cruz’s (ethically questionable) ground game all it’s cracked up to be? Can Marco Rubio restore order to a Republican Party that is in danger of coming apart at its Brooks Brothers seams? We’re about to find out.

Here’s where things stand heading into caucus night (all polls are Iowa specific):

Donald Trump
RealClearPolitics average
: 30.4 percent, up 2.9 points from Jan. 1.
Des Moines Register/Bloomberg: 28 percent, up 6 points from the same poll three weeks ago.
chances of victory: 58 percent.
chances of victory: 48 percent.

Ted Cruz
RCP average: 24.2 percent, down 6.1 points.
/Bloomberg: 23 percent, down 2 points.
polls-only: 32 percent.
polls-plus: 40 percent.

Marco Rubio
RCP average: 15.2 percent, up 3.2 points.
/Bloomberg: 15 percent, up 3 points.
polls-only: 8 percent
polls-plus: 11 percent.

Ben Carson
RCP average: 8.8 percent, down 0.5 points.
/Bloomberg:10 percent, down 1 point.
polls-only: 2 percent.
polls-plus: 1 percent.

No other candidate has cracked double digits in any Iowa poll in more than three months, making it hard to imagine a Hawkeye State surprise from the likes of Jeb Bush or Rand Paul. Here’s what I’ll be watching for when the results start to come in late Monday night.

Is Trump for Real?

Trump is currently the favorite to win Iowa, but victory is hardly assured. He’s been running neck and neck in the polls with Cruz for the past two months, and there remain serious doubts about whether his fans will show up in the numbers necessary to deliver him the win in a contest that is traditionally decided by turnout and on-the-ground organizing. If Trump does win, though, it’s hard to overstate just how big of a deal that would be. Overnight, the former reality TV star would go from polling front-runner to real-life winner of an actual presidential nominating contest, something that seemed truly unthinkable when he unexpectedly entered the race this past summer. Trump would head to New Hampshire—where he’s already up big in the polls—riding even more momentum and media attention than he has now, and could conceivably sweep the first four nominating states before Super Tuesday, the March 1 delegate bonanza chock-full of dark red states. He’d still have his work cut out for him given a primary calendar that is back loaded with delegate-rich blue and purple states that theoretically favor his establishment-minded rivals, but he’d be off and running. It’s unclear who could catch him.

Something else we’d learn from an Iowa win: that Trump’s beloved polls were an accurate reflection of his political strength. That’s a truly terrifying scenario for the GOP given he’s been dominating state and national surveys for the past six months while doing and saying whatever he wants. Today, it’s still possible to convince yourself that there’s a difference between someone telling a pollster they are a Trump fan and actually voting for Trump. Tomorrow, it might not be.

The situation is more complicated if Trump loses. If his final caucus numbers are only a fraction of his support in state surveys, the jig would be up. He’d finally be exposed as the bizarrely coiffed paper tiger that many saw him as this past fall. A narrow loss, though, would be a blow to Trump’s considerable ego, but it wouldn’t be fatal to his campaign. As long as his caucus performance is reasonably close to his polling numbers, he’d remain the favorite in the New Hampshire primary, where a victory would legitimize his candidacy in ways that his polling performances and crowd sizes have been unable to. A Trump win in Iowa could turn him into a juggernaut. A close loss there, though, would only prove he’s mortal.

Can Cruz Survive a Loss?

The same can’t be said for Cruz. He has bet big on Iowa, and if he can’t beat Trump there, it’s unclear where he can. Right now, the Texan’s path to the nomination looks something like this: He and Trump split the early states, and then a terrified Republican Party eventually sides with him in a last-ditch effort to avoid seeing Trump on stage in Cleveland this summer. That scenario looks less likely now that so many of his fellow conservatives have trained their fire on him in Iowa, but it’s still his best and perhaps only shot at becoming the nominee.

Cruz wouldn’t benefit quite as much from an Iowa victory as Trump would—Cruz is cut from the same cloth as the past two caucus winners, Mike Huckabee and Rick Santorum, neither of whom went on to be the nominee. Still, it would give Cruz a serious boost. After drawing fire in recent weeks from Trump, from Rubio, from Iowa’s corn-loving establishment, and even from Fox News, a caucus win after all that would suggest Cruz has the staying power to go the distance. The more immediate payoff, though, would come in New Hampshire, where he’d likely see a sizable post-Iowa bump. That could be enough for him to finish in second place—which would deny Rubio and the rest of his establishment-approved rivals the type of breakout performance they so desperately need. If that happens, Cruz would be one step closer to the one-on-one matchup with Trump that he thinks he can win.

Rubio to the Rescue?

Iowa appears to be a two-man contest between Cruz and Trump, but there are some signs that Rubio is making a late push. He’s spent more time in Iowa than any other candidate over the past three months, and has seen his poll numbers inch up recently. His campaign is being careful to keep expectations low for obvious reasons, but it’s clear they see an opportunity given Cruz’s recent slippage and the ongoing uncertainly over Trump’s ground game. The most likely outcome is that Rubio finishes in third place, just well enough to remain the favorite in the establishment lane but not well enough to cement that status. A surprise second-place—or even the narrowest of third-place finishes—would make Rubio the secondary storyline leaving Iowa, which could be enough for him to pull away from his establishment-approved rivals in New Hampshire. A poor performance, though, might have an even bigger impact on Rubio: If he fails to hit his polling marks, he could fall behind Carson to fourth place, which would leave him looking less like his party’s savior and more like its latest sacrifice.

Elsewhere in Slate: Iowa Is the Must-Win Contest for Bernie Sanders

Read more of Slate’s coverage of the GOP primary.