Yes, but for some reason Rasmussen get’s it right in the end, because he had the 2004 election right on the nose using the same Dem vs Repub percentages.
In 2000 Ras was terrible, calling it +5/+6 for Bush all the time. That was way off. In 2004, he got it right.
Now, he may be oversampling Republicans again. If he calls it O +2, it may be closer to O +3/+4, imo. Yesterday was obviously a very bad polling day for McCain, for no clear reason.
To win, McCain needs to hold all five of CO, VA, NV, OH and FL.
If the election took place today, McCain would lose CO (definitely), VA (likely) and possibly NV and OH as well. He is in about the same shape Kerry was before the first debate. Kerry managed to make it closer, though never quite got back to even in the RCP average.
I don't know that he used the same D vs R percentages. I do know that he screwed up badly in 2000, when he wasn't weighting by party ID, and switched to party weighting in 2004. But I don't remember him giving Ds a six point advantage, and in any event in 2004 the same number of Republicans voted as Democrats (percentages were 37D, 37R, and the rest Is).