You can view Rasmussen's poll numbers from the '08 race
here. Unfortunately, the numbers only go to October 15th, as that was the latest date I could get on the election.
You'll notice, though, that in October, the entire month, actually, Obama led McCain. His highest lead was 8 on the 6th and 7th - while his narrowest lead was six on the 1st. He was leading, though, for the last part of September. In fact, the last day McCain led Obama was 9/17.
Now RCP's
average of the polls in '08 shows that Rasmussen had Obama winning the election 52-46, or +6.
But those polls don't appear to be released every single day. So, who knows in that regard.
Anyway, let's compare the Rasmussen numbers with RCP's average from August 1st to October 1st. I think that'll give us an indication of how similar or off the numbers were. And I'm gonna do every few days so that it's not too terribly long.
(R: Rasmussen, A: Average)
08/01/08 - R: +1, A: +2.6
08/05/08 - R: -1, A: +2.5
08/10/08 - R: +2, A: +4.4
08/14/08 - R: +1, A: +4.2
08/18/08 - R: +1, A: +3.6
08/20/08 - R: +1, A: +1.2
08/24/08 - R: +3, A: +1.7
08/28/08 - R: 0, A: +2.9
08/30/08 - R: +4, A: +3.9
09/01/08 - R: +3, A: +5.5
09/05/08 - R: +2, A: +2.6
09/07/08 - R: 0, A: -1
09/10/08 - R: +1, A: -2.2
09/14/08 - R: -3, A: -2.1
09/17/08 - R: -1, A: 0
09/20/08 - R: +1, A: +2.3
09/24/08 - R: +2, A: +3.5
09/28/09 - R: +6, A: +4.8
09/30/09 - R: +6, A: +4.8
Looking at these numbers, the difference isn't huge. In fact, the average of Obama's lead in the polls in Rasmussen through this stretch was 1.5 and the average in the average was 2.3 - or .8% - less than an entire percentage point.
With that in mind, it's hard to say Rasmussen's numbers lagged that much. Then again, .8 in a relatively tight race, as it was back at that point in '08, makes a big difference - especially when it's possible those same Rasmussen numbers were being weighed in the daily averages.
Plus, I didn't look at it every day, so it's certainly not exact. But you get the idea.
My problem with Rasmussen isn't that he's showing Obama trailing. It's that now Romney has done a complete 180 in support since Obama was leading by roughly eight points last week. For something like that to happen, you would think there would need to be a massive scandal because a double-digit swing in only a few days is almost unheard of, especially when there really is nothing going on in the news to force that change.