When I first read Bruce’s math post, I noted the percentage of Obama supporters who have declared for Romney and wonder if those who hadn’t yet committed either way were like Ann Althouse and or were double-downers, who in the end will double down on their 2008 bet. Since I’m not privy to their inner workings
First, let’s start with the popular vote results from 2008. Obama, 52.87%; McCain, 45.6%.
Bruce’s chart showed Obama keeping 84% of his 2008 vote, with 13% already defecting to Romney, leaving 3% up for grabs. Now, in August, Gallup released a poll showing that Romney was only getting 92% of McCain’s 2008 vote, with Obama getting 5%.
Let’s start with what Obama has. .84 x 52.87 = 44.41%. Now, add in Obama 5% of the McCain vote. .04 x 45.6 = 2.28%. That gives Obama a base vote of 46.69%, roughly 47%.
On to Romney. He starts with the McCain base .92 x 45.6 = 41.95%. Now, add it that 13%. .13 x 52.87 = 6.87%. That gives him a base vote of 48.82%. And that’s without accounting for the disaffected Republicans who didn’t vote in 2008.
This math shows Romney up 2 points over Obama, likely more given GOP enthusiasm. And it may be a tad conservative, given that the Gallup poll was conducted before Romney had tapped Paul Ryan as his running mate or showed his qualities in the three debates.