The generic ballot is only for the House; it's my understanding it doesn't include Senate races.
Vorlon, is there any particular reason why the generic ballot leans Democratic? I remember hearing that the Dems did win the popular vote for the House overall in 1996, but I'm assuming the GOP won it in the other years you listed.
I'm not disputing that it is inaccurate as it clearly is, but why is this true? Why are people more likely to say they are voting Democratic and then end up voting Republican than the opposite? I guess I'm just perplexed as to why it would always be off, and always towards the Dems.
In any event, if it is always about 4-5 points too Democratic, we can then just adjust for that and get the real results. Consistency matters more than accuracy.
I think people are always mad at Congress, so they always want the opposition party to win it back. However, they still vote for their own local Congressman (which in most cases have been a Republican during the last decade)