The conventional wisdom going into the Iowa caucuses held that, if voter turnout was high, Donald Trump would take the state. The Real Clear Politics average of polls showed a solid lead, the “gold standard” of Iowa polls said the same, and his closest competitor, Ted Cruz, wasn’t as popular in the state as before. But what actually happened Monday night confirmed another, perhaps quieter suspicion among primary-cycle observers: that Cruz’s ground game, and greater support among evangelicals, would carry the day.
For those shocked by the GOP results, take heart: Iowa is notoriously fickle, and not even top pollsters firmly predicted a win for Trump or Cruz, despite assumptions to the contrary. And it’d be wise to steel yourself for more unpredictability in the minutes, hours, and days leading up to next week’s primary in New Hampshire.
“We really do tend to look at [polls] as if they are somehow predictive...The best you can do is approximate and, if you’re a pollster, hope that the trends don’t shift on you,” David Redlawsk, the director of the Rutgers-Eagleton Poll, said with a laugh. “But they often do.”
When pollsters talk about polls—their own or others’—they’re always quick to offer a litany of warnings: Surveys have margins of error for a reason, to account for sampling mistakes; methodologies can vary wildly, depending on the pollster; and polls are just “snapshots” of voter sentiment in time. For some, uncertainty keeps the election season exciting. “The reality is, we release our poll, stand by our method as our best shot, then obsess about how things could change on caucus night,” said J. Ann Selzer, the Des Moines Register polling maven who runs that “gold standard” survey, in an email. “If you are a political junkie, interested in how people make decisions in this democracy, this is all part of the thrill!”