Sorry, GOP: Polls Aren't Biased Also, a rundown of the latest polls By Polly Davis Doig, Newser Staff Posted Sep 30, 2012 1:21 PM CDT 60 comments Comments In 2012 file photos, President Barack Obama and Mitt Romney. (AP Photo/Scott Applewhite, left, and Evan Vucci, file) (Newser) – The GOP has spent a lot of time lately decrying the bias driving polls that show President Obama opening up a lead over Mitt Romney, but Nate Silver takes a look at how final polls have historically performed against results, and finds that while they have occasionally missed the mark, "polls have no such history of partisan bias," he writes at FiveThirtyEight. The biggest miss was in 1980, when late polls showed Ronald Reagan with a 2- or 3-point lead; he ended up trouncing Jimmy Carter by 10 points. But that election was made unusually volatile by a single, late-in-the-cycle debate that didn't have time to register in polling and the presence of a third-party candidate, Silver says. In the 10 elections since 1972, polls have "overestimated" Dems' edge five times, the GOP four times, and nailed Barack Obama's margin of victory on the head. Accusations of partisanship, concludes Silver, are most likely "wishful thinking." Click for Silver's full column, or take a look at a few of the latest polls out there: In Ohio, Obama has opened up a 51% to 42% lead over Romney, reports the Columbus Dispatch. In Iowa, the incumbent is leading Romney by 49% to 45%, according to a poll out yesterday by the Des Moines Register. But with widespread disapproval over Obama's economic stewardship, Romney has an opening. In Massachusetts, Elizabeth Warren has opened up a 43% to 38% lead over Scott Brown in their closely contested Senate race, according to a Boston Globe poll. But with a debate set for tomorrow night and a hefty 18% of voters undecided, that number could swing substantially.