Rasmussen was on O’Reilly this morning, and he was all but saying “stick a fork in McCain.” He said most people already believe (according to his poll internals) their taxes will go up under Obama, and most people believe Obama will raise spending, etc. In other words, the attacks have worked in making people believe the things said about Obama are true - yet they will vote for him anyway. Rasmussen posits that McCain has become irrelevant, this is a referendum on Bush.
It is about turnout. In 2006 more Democrats and Democratic-leaning Independents turned out to vote to the tune of 9.4% for the Senate and 5.4% for Congress. That is why the pollsters call their models TURNOUT models.
Besides, there is evidence that party identification has changed since 2006:
http://pewresearch.org/pubs/773/fewer-voters-identify-as-republicans
“In 5,566 interviews with registered voters conducted by the Pew Research Center for the People & the Press during the first two months of 2008, 36% identify themselves as Democrats, and just 27% as Republicans.
The share of voters who call themselves Republicans has declined by six points since 2004, and represents, on an annualized basis, the lowest percentage of self-identified Republican voters in 16 years of polling by the Center.
The Democratic Party has also built a substantial edge among independent voters. Of the 37% who claim no party identification, 15% lean Democratic, 10% lean Republican, and 12% have no leaning either way.”
and this:
http://abcnews.go.com/images/PollingUnit/ABCWashPostPartyID.pdf
While I don’t think Rasmussen’s model is 100% accurate as for the exact advantage Democrats have, Scott Rasmussen (who after all is not a flaming liberal by any means) is not making these numbers up, either. They are arrived at via separate surveys to gauge party identification on an ongoing basis:
“The targets are not set arbitrarily. Rather, they are established based upon survey interviews with a separate sample of adults nationwide completed during the preceding six weeks. A total of 500 nightly interviews are conducted for a total of 21,000 interviews over the six week period.
This week’s adjustment shows a three-tenths of a point increase in the number of Democrats and an identical decline in the number of Republicans.
For polling data released during the week of October 5-11, 2008, the partisan weighting targets will be 39.3% Democratic, 33.3% Republican, and 27.4% unaffiliated. For the preceding week, September 28-October 4, 2008, the partisan weighting targets were 39.0% Democratic, 33.6% Republican, and 27.4% unaffiliated.”