Winning Iowa would mean a great deal for Donald Trump. As we have seen since the advent of the modern presidential primary system winning Iowa or New Hampshire matters. In fact, since then, every single nominee but one in both parties won either Iowa or New Hampshire. For Trump, it would mean that he stopped his chief rival, Texas Sen. Ted Cruz, in a state where evangelicals made up nearly 60 percent of self-identified GOP caucusgoers in 2012. Evangelicals are an audience Cruz has courted heavily, and Iowa, which supported Mike Huckabee and Rick Santorum in the past, appears tailor-made for his Christian conservative message. There Cruz has built a traditional field organization aimed at mobilizing his supporters on caucus day, but Trump has taken an unconventional approach. Instead of boots-on-the-ground, Trump has relied in significant part on earned media to build enthusiasm, and he received a boost last week with a well-timed endorsement from Sarah Palin, a darling among tea-party supporters and evangelicals. A CNN/ORC poll released on Thursday showed Trump opening up a 9-point lead, but Cruz still fares better among evangelicals. In a recent NBC News/Wall Street Journal/Marist Poll, Cruz leads Trump 33%-19%. Arguably, a Cruz win is less of a predicament for the other GOP candidates, but a Trump win would be very problematic. Right now, Trump is a 20-point favorite in New Hampshire. He’s led in every poll there since last July and has even gained ground recently. Since 1976, no GOP presidential candidate, excluding incumbents, has ever won both early states. Winning Iowa and then New Hampshire this year, in this political climate, could make Trump very difficult to stop.