IMHO, the polls are "screwy" for one reason, and one reason ONLY - a massive (Republican) voter suppression effort by the bought-and-paid-for media (which owns/runs the pollsters). There are a couple of decent polls out there, but every single one that far more heavily weights Dem voters vs. historical averages is off - so off as to be purposeful.
I have no data, nor am I a statistician. But I have some common sense. People don't switch party affiliation overnight - though they may suddenly like or not like a particular candidate. What held in '04 is probably going to hold, with a very small change, this cycle. Here are two factors NOT accounted for by the polls: 1) Almost all of the fraudulent ACORN registrations are undoubtedly Dem, thereby skewing the results; and 2) NONE of the polls takes into account the Operation Chaos effect - this is, people like me who registered Dem specifically in order to mess with their primary process (as they did with ours in SC and elsewhere). Me. I'm a registered Dem. Ha! Ha! Ha! Ha! Ha! Ha! Ha! Ha! Ha! I already voted for McCain, even though I don't care very much for his politics - because I greatly FEAR Obama and Dem lock on 2 of the branches of the Fed.gov.
Get ready, folks: Among our group there will be great Schadenfreude next week; among the Dems, there will be great gnashing of teeth and far higher than usual psychologists' bills.
Just remember to vote, and encourage everyone you know who'll vote against Obama to do the same.
I saw someone post earlier that Operation Chaos is partly to blame for the pollsters changing the party weighting system.
There were a lot of Republicans that registered as Dems, plus the huge Acorn push, that is confusing the poll companies.