The FiveThirtyEight Team Goes To Iowa

I-35 EAST (near Urbandale) — We all know that Donald Trump likes to cite polls that have him ahead, but he seems to be particularly fond of Gravis Marketing. At his rally in Cedar Falls yesterday, Trump started his poll summary by mentioning a Gravis national poll showing him at 41 percent. And today, he tweeted out a Gravis poll showing him leading in Iowa with 34 percent. https://twitter.com/realDonaldTrump/status/687353545063030784?p=v The problem? Gravis has a heavy pro-Trump house effect. According to a FiveThirtyEight analysis, Gravis polls, on average, put Trump 6 percentage points higher than the average pollster. Isn’t it possible Gravis is right? I’d consider it more likely if Gravis had a better track record. FiveThirtyEight’s pollster ratings give Gravis only a C rating. The Des Moines Register poll released Wednesday morning, conducted by Selzer & Company, found Trump at 22 percent in Iowa, trailing Ted Cruz’s 25 percent. Selzer has an A+ rating.