The Washington Post's Dan Balz writes this weekend on Mitt Romney's difficulties against Barack Obama as the campaign enters its final months:

The head-to-head polls have largely remained static in that time. But in looking at the numbers nationally and in the battleground states, the consistency of Obama’s lead is striking. More than two dozen national polls have been conducted since the beginning of June. Obama has led in the overwhelming number of them. Polls in the most contested states show a similar pattern. In three of the most important — Ohio, Florida and Virginia — there have been roughly three dozen polls total since April, about the time that Romney’s GOP rivals were exiting the nomination race. In Ohio and Virginia, Obama has led in all but a few. In Florida, Romney has done better, but overall, Obama has led about twice as often. Those polls are not definitive predictors of the November outcome, by any means. A movement in the national numbers, which could easily occur in the final weeks, will change the look of many of those states. But at this point, the available evidence suggests that the advantage, however small, is with Obama. If this were truly a dead even race, Romney should be ahead in these polls almost as often as he is behind.

Read the whole thing here.