The final Des Moines Register poll was just released, showing Donald Trump leading the Republican field in Iowa with 28 percent, Ted Cruz with 23 percent and Marco Rubio with 15 percent. Hillary Clinton was ahead of Bernie Sanders, 45 percent to 42 percent, on the Democratic side. The political world — us included — was eagerly awaiting this survey, as Ann Selzer, who has conducted the Register’s polls since the 1988 caucuses, has a very good track record. But just how predictive of the final results have Selzer’s polls been? History suggests they’re a good indicator of what will happen in Monday’s Iowa caucuses, though there is room for a candidate or two to surprise.
Why This Is the Iowa Poll That Everyone Was Waiting For
Perhaps no political poll is more eagerly anticipated and receives more attention than the last Des Moines Register poll before the Iowa caucuses.
This year, the final Des Moines Register/Bloomberg survey shows Hillary Clinton leading Bernie Sanders by three percentage points, 45 to 42, and Donald Trump leading Ted Cruz by five points, 28 to 23 percent.
The hype ahead of the survey is easy to understand. Conducted by Ann Selzer, it has one of the most impressive track records in polling — nailing the results even when many other polls predict a different outcome.
The Selzer poll became famous in 2008 when it showed Barack Obama winning with a stupendous turnout from voters who hadn’t previously participated in the caucus. In the 2014 midterm election, the survey found Joni Ernst winning her Senate race by a comfortable seven-point margin — no other poll showed Ms. Ernst ahead by even four points. She won by eight points.