Memo to Survey USA: Stop polling on Sunday

Suvery USA has a poll that is sure to make the rounds (if it hasn’t already): it has Obama up 4, a six point shift from its last poll.

The idea that the race can shift that quickly in one week surprised me, especially since it was supposedly men and older voters that led the shift, and that Obama gained in every region except Northern Virginia.

So, I took a look at the demographics, and lo, the change became obvious: the “new” poll had a six-point drop in conservative voters, four-point drop in regular churchgoers, and a five point drop in pro-lifers.

I don’t see that happening in a week, do you?

This is what happens when you poll on Sunday.  The numbers clearly show that regular churchgoers are more likely to support McCain (and Republicans in general).  Sometimes you get them; usually you don’t (it also explains why McCain has persistently underperformed in the Survey USA Virginia poll – he’s only led once, and that was last week).  Add to it the fact that the Redskins home opener was yesterday at 1 (last week they played on Thursday night – outside the survey time frame), and you have a recipe for serious trouble.

This isn’t to say Virginia’s not competitve.  It is to say that polling in this state that includes a Sunday sample must be taken with a lump of salt.