First, from The Hill's Mark Mellman, who notes that most of the "fundamentals" (such as economic trends, demography, etc.) all favor a Barack Obama win. Snippet:
The president retains more routes to 270 electoral votes than does Mitt Romney, making it more likely he will succeed in getting there. Pundits love to identify one state as decisive and, as is often the case, they've picked Ohio. As an Ohioan I am delighted with all the attention to the Buckeye State, but it's overdrawn. Obama can win without Ohio, though Romney probably cannot. The good news: Just one of the last 11 polls in Ohio has shown a Romney lead, and the exception was the reliably Republican Rasmussen. While all these polls show the race close and even tied, the likelihood of Romney winning unless some other polls start to give him the lead is low.
And here's RealClearPolitics' Sean Trende, who puzzles over the divergence in national polls (which are showing Mitt Romney up slightly over Obama) and state-level polls, which give Obama an edge.
Given what we know about how individual states typically lean with respect to the popular vote, a Republican enjoying a one-point lead nationally should expect a three-to-four-point lead in Florida, a two-to-three-point lead in Ohio, and a tie in Iowa. Instead we see Romney ahead by roughly one point in Florida, and down by two in Ohio and Iowa….
If the state polls are right, even assuming Romney performs as well as Bush did in the states without polling, Obama should lead by 1.18 points in the national vote. Given the high collective samples in both the state and national polling, this is almost certainly a statistically significant difference. It's also a larger margin than all but one of the polls in the national RCP Average presently show.
But what if my assumptions about the states without polling are incorrect? To double-check this, I turned to Drew Linzer's "Votamatic" model. It provides estimates for all 50 states. While some of these seem a bit off (I would bet $10,000 of Mitt Romney's money that he will win Tennessee by more than 10 points), it still gives us a nice uniform data set. The result: When weighted by 2008 voting patterns, these data suggest that Romney should lose the popular vote by 2.5 points—more than any national poll is presently showing.