I want to highlight something...

Down in the methodology post something important is buried.  I think it needs its own post.

What really happened in 2008?

If you listen to the stories of the Hope and Change enthusiasm, you would think that the Democrats got millions upon millions of new voters to show up at the polls and vote for them.  This is compounded by the turnout discussion we use regarding 2008, "It was a D+7 year".

But what does D+7 really mean?

In 2004 122 million people voted.  The partisan ID of those votes are:
D 37% - 45.1 million
R 37% - 45.1 million
I 26% - 31.9 million

In 2008 131 million people voted. The partisan ID of those votes are:
D 39% - 51.1 million
R 32% - 41.9 million
I 29% - 38 million

So the actual changes from 2004 to 2008 are:
D + 6 million
R - 3.2 million
I + 6.1 million

The combination of Republicans staying home and additional Independent voters is 50% higher than the number of new Democrats that showed up.

It shows clearly why Obama is running the campaign he is running.  He needs to do three things. 

1. He needs to keep his base voting at historic levels.  
2. He needs to keep Republicans at home like they were in 2008.  
3. And he needs to make Romney toxic to Independents.

How is that working out for him?

A lot of reports are out there that Democrat enthusiasm is low, however the Dem convention did help him, so we can give him a solid B+.

Republican enthusiasm matches or exceeds Democrat enthusiasm whenever it is measured.  There are a lot of broken glass voters against Obama.  Call this a D-.

Finally every poll shows at least 50/50 support among Independent for Romney, sometimes much higher.  So this is a failure, I'm giving him an F here.

So a back of the envelop expected result for 2012 looks like:
D - 50 million
R - 52 million
I -38 million (at a 52/48 split it would be 19.8m Romney/18.2m Obama)

Obama: 68.2 million votes
Romney: 71.8 million votes