The perennial question about election polls is back again, if ever it left: how far can we trust them? Should we disregard all other evidence but what the current polling of individual Senate races tells us – which is, at this writing, that if the election was held today, Republicans would gain 6 seats in the Senate to hold a narrow 51-48 majority? As usual, a little historical perspective is in order. It is mid-September, with just over seven weeks to Election Day, and as discussed below, all the fundamental signs show that this is at least a mild Republican “wave” year. A review of the mid-September polls over the last six Senate election cycles, all of which ended in at least a mild “wave” for one party, shows that it is common for the “wave party” to win a few races in which it trailed in mid-September – sometimes more than a few races, and sometimes races in which there appeared to be substantial leads, and most frequently against the other party’s incumbents. Whereas it is very uncommon for the wave party to lose a polling lead, even a slim one, after mid-September – it has happened only three times, one of those was a tied race rather than a lead, and another involved the non-wave party replacing its candidate on the ballot with a better candidate. If these historical patterns hold in 2014, we would therefore expect Republicans to win all the races in which they currently lead plus two to four races in which they are currently behind, netting a gain of 8 to 10 Senate seats.
The Mid-September Polls: Still Waiting For The Wave
When I last reviewed the Senate races in late June, the picture we saw was that Republicans had largely locked up three races for open seats currently held by Democrats – in Montana, South Dakota, and West Virginia – and locked down the one GOP Senate seat in deep-blue territory, in Maine. That left nine heavily contested seats, mostly in red or purple states (plus blue Michigan, the toughest race) and four other purple or blue state races in which the GOP had not yet become competitive, but retained hopes of bringing the race into its sights:
As I noted at the time, this left Republicans “waiting for the wave” – hoping that fundamental factors like …read more