Midterm predictions: Sam Wang says Dems. have a 70% probability of holding the Senate
Sam Wang of the Princeton Election Consortium, is not as well known as Nate Silver of Five Thirty Eight, who was the media darling in the 2008 and 2012 elections with his amazing predictions for the Presidential elections and midterms. Despite current predictions by the Washington Post, the New York Times, Larry Sabato, Sam Wang currently is predicting the Democrats will keep control of the Senate, albeit by a razor thin margin.
Senate Democrats are doing surprisingly well. Across the board, Democratic candidates in the nine states above are doing better in the polls-only estimate than the mainstream media models would predict. This is particularly true for Alaska, Arkansas, and North Carolina. In these three states, Democrats are outperforming the expectations of the data pundits (The Upshot’s Leo, Nate Silver, Harry Enten, John Sides, etc.).
Currently, the long-term forecast for Democratic control on Election Day is 65%, about 2-1 odds in favor.
I’ve been asked why the PEC Senate poll snapshot is more favorable to Democrats than forecasts you’ll find elsewhere: NYT’s The Upshot, Washington Post’s The Monkey Cage, ESPN’s FiveThirtyEight, and Daily Kos. All of these organizations show a higher probability of a Republican takeover than today’s PEC snapshot, which favors the Democrats with a 70% probability. Today I will show that in most cases, added assumptions (i.e. special sauce) have led the media organizations to different win probabilities - which I currently believe are wrong. I’ll then outline the subtle but important implications for a November prediction.
Dr. Wang explains his methods why everyone else is missing what he sees. Sam Wang's predictions were even more accurate than Nate Silver's predictions, getting every close Senate race right in 2012 when Silver missed 2 of them.
Dr. Wang also wrote a lengthy article explaining his modeling.