Trump has averaged 24.5 percent and 33.2 percent in non-live polls in Iowa and New Hampshire, respectively. In live-interview polls in those same states, he has averaged 20.4 percent and 22.3 percent. In surveys released the same November weekend, Suffolk University found Trump’s support at 22 percent in New Hampshire, while YouGov released a poll pegging him at 32 percent. Imagine if this gap holds up through early February: It’s possible that we’ll head into Iowa and New Hampshire with little idea of what’s going to happen.

And it’s not just a matter of good pollsters versus bad pollsters: Every online pollster has averaged more Trump-friendly results than the live-interviewer average. NBC News, SurveyMonkey and The Wall Street Journal all typically conduct top-notch polls. SurveyMonkey, for example, was one of the few pollsters to do well in the 2014 U.S. midterms and 2015 United Kingdom elections, and the NBC News/Wall Street Journal poll earns an A- in FiveThirtyEight’s pollster ratings. Yet, Trump has averaged 26.8 percent in the NBC News/SurveyMonkey surveys1 conducted online and 22 percent in the NBC News/Wall Street Journal polls done live by phone. In many instances, they have produced different results within days of each other…

Who might have a better handle on Trump? It’s difficult to say because there are pollsters I trust on both sides of the divide. There are a lot of smart people at SurveyMonkey and YouGov. SurveyMonkey, especially, has done ridiculously well recently. We can’t test anything until the voting starts, so at this point, it’s probably best to take both live-interview and non-live-interview polls into consideration.