That’s within the margin of error, but Trump leads of any sort have been scarce in Iowa lately. He also topped Cruz in the last Quinnipiac poll of the state taken in early and mid-December, 28/27, and led narrowly in a PPP poll of Iowa taken around the same time. But of the last 10 surveys conducted there, those were the only two where he took first. He trailed Cruz in the other six and tied him in another.

Is this statistical noise or Cruz’s grasp beginning to slip?

Note the last two columns. Among college grads, Cruz leads comfortably by seven. Among non-college grads, Trump leads comfortably by eight. That’s not the first time we’ve seen that divide in primary polling this year. Bearing that in mind, have a look at what Quinnipiac found when they asked Iowans if they’ve ever caucused before or if this is their first time:

Who are the two biggest cohorts of first-time caucusgoers? Right: Non-college grads and moderate/liberal Republicans, the two pillars of Trump’s base. If they’re true to their word and Trump ends up turning out droves of voters who’ve stayed away from the party in the past, Cruz will have his hands full next month. That said, Cruz and Marco Rubio are both well regarded by Iowans without college degrees — even more so than Trump is, believe it or not. Cruz leads the field in favorability (a growing trend lately) at 75/17 overall with a nearly identical number of 76/16 among non-college grads. Rubio’s numbers are 67/22 and 65/24, respectively. Trump’s are 61/34 and 64/31. Enough ink has been spilled on how different Trump fans are from rank-and-file Republicans that it seems weird and surprising that his base is derived from a pool of people who are well-disposed towards establishment favorite Rubio, but that’s what the data here says. In fact, if you’re looking for demographic groups that view Trump noticeably more favorably than Rubio, you should skip the non-college grads and focus on ideology. Among tea partiers, Rubio’s favorables are a healthy 66/25. Trump’s are … 75/21. (Cruz’s are an astronomical 91/6.) Bet you didn’t see that coming circa 2011.

All things considered, in fact, this is a good poll for Rubio. No one expects him to win the state; a respectable third with a surprisingly strong finish might be all he needs to finally break the center-right logjam in New Hampshire. He could easily crack 20 percent in Iowa if Christie, Kasich, and Bush fans there start abandoning their guys as lost causes and caucus for Rubio to give him some momentum in NH. It’s hard to see him coming all the way back to threaten for second place, though. When you dive more deeply into Quinnipiac’s crosstabs, you’ll see that it’s a two-man race on all the major issues. On the economy, terrorism, and taxes, Trump leads Cruz big. On foreign policy, social issues, and personal traits like trustworthiness, experience, and caring about the problems of people like you, Cruz outpolls Trump, sometimes handily. What could possibly happen over the next month to somehow insert Rubio into the thick of a battle between the staunch conservative Cruz and the angry populist Trump? How does Rubio get to, say, 30 percent? Or does it matter, given how low expectations are for him in Iowa?

Meanwhile, Jeb Bush is at three percent. I guess the billboard didn’t work, huh? Exit question: Will Trump’s attacks on Cruz’s eligibility ultimately tip a close race in Iowa his way? Or will it be … another issue that does it? I can’t imagine a more encouraging sign of the Republican Party’s health than if Trump won the caucuses on a mix of Birtherism and ethanol pandering.