I don't know what to make of this, but the LA Times is reporting that Romney is currently off the air in at least large parts of Ohio. While withdrawing from Michigan and Pennsylvania might make a certain amount of sense, there's really no scenario in which Romney can win without Ohio, nor is there any clear reason for him to pull ads there. Maybe someone can shed light on this:
[F]or reasons that his advisors declined to discuss, Romney has ceded the advertising airwaves to Obama over the last week in Ohio and other battleground states.
The sudden cease-fire offered a surprising lull in what for months had been a guns-blazing advertising war waged in Ohio, Florida, Virginia, Nevada, Colorado, Iowa and New Hampshire — on one side, Romney and his allies; on the other, the president and his.
...
But Romney’s temporary withdrawal has been striking here in northern Ohio, where what had looked to TV viewers for months like an evenly matched, if annoying, ad battle transformed into a lopsided all-Obama/all-the-time promotion campaign, with news coverage of the Democratic National Convention amplifying the president’s message.
The Romney vacuum was especially noteworthy given that early voting in Ohio starts in less than four weeks.
2:22 PM PT: And like that, TPM is now reporting that Romney is planning a new $4.5 million ad buy in eight states, including Ohio. Still a strange decision to go dark for any length of time, at this fairly late stage in the race.