WHY YOU SHOULDN'T BELIEVE THAT FOSTER McCOLLUM POLL OF MICHIGAN

In contrast to a lot of other polling from Michigan showing Obama ahead, the local Fox affiliate has a poll of the state showing the race tied. Don't be fooled.

Why shouldn't you believe this poll? Because the polling firm, Foster McCollum White Baydoun, has a likely voter screen that's utterly absurd, as Nate Silver explained a while back:

In Michigan, there are two local polling firms in particular that have shown poor numbers for Mr. Obama. One is ... Foster McCollum White Baydoun, which had Mr. Romney ahead by four points in its last survey.

Foster McCollum White Baydoun actually does survey one state apart from Michigan: it released a poll of Florida last week. In that survey, it showed Mr. Romney ahead by almost 15 points -- perhaps the biggest outlier we’ve seen in any individual poll so far this year.

As I mentioned when that Florida poll came out, this firm anticipates a big decline in participation among groups like younger voters that are ordinarily inclined to support Democratic candidates. The initial news release of the Florida poll appeared to show that the firm anticipated that just 11 percent of Florida voters would be under age 50 -- in contrast to about half the Florida electorate in 2008, according to exit polls. A principal of the firm, Eric Foster, later wrote me to say that the news release had been incomplete, and voters under the age of 50 had actually been weighted to make up 27 percent of the poll instead.

That's still an implausibly large drop-off, in my view, from 2008. It may be because the Foster McCollum White Baydoun likely-voter model looks for voters who, as they described it, participated in "odd year municipal and county elections" -- where turnout is tiny as compared with what it will be on Nov. 6. In any event, this method seems likely to produce extremely Republican-leaning results -- whether applied to Michigan, to Florida or to any other state.

A firm that thinks three-quarters of the electorate will be 50 or older, even in Florida, is not going to get believable results.

I've seen a tweet, which I can't find now, that says the current Michigan poll has a similar huge age distortion, greatly tipped toward older voters. (Curiously, when you go to the Fox story and try to click on the link to get full results, the link doesn't work.)

Don't believe this poll.