Now, however, Obama has opened up advantages in raising money at the same time as he's pulling ahead slightly in the polls. How did he accomplish this? This ABC article may have the best explanation: the Obama campaign spent a lot of money on TV ads in swing states during both conventions, making sure that his message was heard during those news-saturated weeks. The Romney campaign lagged in TV ad placement.
I wonder whether Romney was keeping his powder dry for a blitz in October. By that time, it may be too late. The Romney campaign and his allied superPAC can dedicate a lot of cash to ads, but the Republican National Committee, which is flush this year, and other rich superPACs may shun Romney and instead devote their resources to more promising races, like Senate seats and control of the Senate.
Perhaps TV saturation wouldn't help anyway. Repetition of the same talking points grates on undecided voters. A more empathetic narrative might work, but Romney hasn't shown that he knows how to frame one. With six weeks left, Romney's hopes depend on increasingly unlikely events--a major Obama fumble, a foreign or domestic crisis that demonstrates an unknown blindness in the Obama administration, a compelling debate performance by Romney that leaves Obama speechless.
I doubt that any of these black swan events will occur. Romney may not be toast yet, but he's in the toaster and really close to those glowing filaments.