It's been one day since we launched our election forecasting hub. In the week or so before that, the polling news had generally been good for Democrats. As a result, the forecasting models — including those that had tended to favor Republicans — were mostly showing slight Democratic leads or pure 50-50 tossups. But when new polls come out, these models move too — and after one very bad day of polling for Democrats, the models are moving towards the GOP:
The biggest movements were a 7 point gain for the GOP in the Upshot's model, and a 9 point gain in the Daily Kos model. Now, these movements are still small. But both of these models are now giving the GOP a very narrow edge, which they weren't yesterday.
Why the models moved
Yesterday, Democrats got bad polling news in three key races — Iowa, Colorado, and Louisiana.
In Iowa and Colorado, the GOP candidates — Joni Ernst and Cory Gardner —hadn't led a single poll in weeks. But yesterday, a new Iowa poll showed a tied race, and another showed Ernst ahead by six points — a bigger lead than her opponent Bruce Braley has had in any recent poll.
Meanwhile, in Colorado, one poll showed Gardner down by only 2, and another showed him ahead by one. (Another, just released this morning and not yet factored into the models' projections above, shows Gardner up by 8.)
Then, in Louisiana, the sense that the Deep South Democratic seats are slipping away was further confirmed by a poll showing Republican Bill Cassidy beating Mary Landrieu by 13 points in a head-to-head matchup.
The polls showing Ernst up six and Gardner up eight are both from the same firm (Quinnipiac), and some analysts are viewing their results with skepticism. Several other polls mentioned here are from Fox News. But the forecasters, for the most part, don't pick and choose which polls to include, since that could easily turn into cherry-picking. They prefer including many polls and then relying on polling averages — and these new data points move those averages. In Iowa, almost every modeler now shows Ernst with a slight lead.
This new polls should be taken as provisional. But they do cut against the growing sense that the purple states were moving in the Democrats' direction — and they show just how close the Senate battle remains.