At National Review Online, Jim Geraghty notices a trend that has bothered Townhall readers for some time now-polls that are skewed towards Democrats. Geraghty posts an email from his number-crunching correspondent, bemoaning the blantant oversampling:
On another polling annoyance, I turn to your favorite punching bag PPP-D. Here is the trend with PPP-D. They do a terrific job polling our primaries (this is not sarcasm). Their closing polls are usually okay. But their tracks, should be involving a Republican versus Democrat race be viewed with healthy skepticism. The latest poll release in NC showing Obama +1 indicated a Democrat advantage of +12. I don’t know what they are smoking over there but I want some (just kidding) . . .
As I tracking every public poll, I have found it amazing on how many pollsters are oversampling Democrats. On average, every poll is indicating a partisan ID similar to 2008. Based on my analysis, the average gap is +6.4% Democrat which compares to the +7% which was in 2008. Alas, for the RCP poll average to be correct you have to assume the self-identified party preference turnout will be similar to 2008, if the turnout is similar to 2004 or 2000 or 2010, Obama’s polling leads may as well be part of his “story telling.” For the pollsters that look at preference, Rasmussen has indicated that the self-identified party ID (for Adults – not likely voters) is about +1.4% Republican.
Based on my track if the election were held today Romney wins by 5 percentage points.
We have reported this trend whenever we see it. One possible reason is that not everyone who is a registered Democrat actually votes that way. Geraghty notes that in North Carolina, for example, there actually are many more registered Democrats than Republicans, though Democrats tend to lean conservative.
Irritating for sure, but the good news is that President Obama seems to be losing ground even when given a sampling boost. And that in four months, we won't have to hear the media alternately slanting the polls, then patting the president on the back as they try to help him out.
