Fred Bauer argues that the Democratic internal poll cited by Jonathan Martin earlier has a sample with way too many Democrats and not enough independents. If turnout matched voter registration, Democrats would make up 36 percent of the sample, not 49 percent.

I think he’s in the right ballpark, although I’d note we’re all more or less taking a guess on how the electorate will look in a special election. Would independents and unaffiliateds be the least likely to show up in a mid-January special election? Or does the “meh” nature of the Coakley campaign, coupled with the fired-up Brown campaign, mean that Democrats will make up a smaller slice of the electorate than usual?