One of the great polling mysteries of the 2012 is the fact that President Barack Obama and Mitt Romney are deadlocked in national polling, but the state-level polling shows a much more comfortable Obama lead.

Case in point is Pennsylvania—a state more critical for Romney's chances than Obama's. Yet polling hasn't shown much of a contest. PPP has the latest numbers:



PPP's newest Pennsylvania poll finds things have changed very little in the state over the course of the last ten weeks. Barack Obama leads Mitt Romney 50-42, basically the same as his 49-42 advantage there in early March.

Two weeks ago, Quinnipiac University had Obama leading 47-39 in the state. Several other university polling operations gave Obama big leads earlier in the year. Meanwhile, Rasmussen has been strangely AWOL in the state.

Looking at the big picture, the current state of the race (using TPM's polling composites):



North Carolina has flipped because of a recent Rasmussen polls showing Romney leading 51-43 (something no one else has seen). There hasn't been any new polling in New Hampshire, so it looks like an old Romney-friendly poll must've rolled off the average. And Wisconsin tightened because of our recent PPP poll showing Obama with just a 1-point edge. The catch? The sample was of likely recall election voters, and we are seeing a real intensity gap in Wisconsin for the recall.

Add it all up, and our map is still a comfortable 294-235 Obama victory (with Colorado's nine electoral votes unassigned). And if you look at the polling margins, Obama's leads are far more comfortable than Romney's in the states he leads.

Now consider states like Tennessee, where Romney's lead is less than impressive, and those tied nationwide numbers look particularly out-of-whack. (And yes, that includes our very own.)