Wasn’t Ohio in a similar spot in 1982? The recession disillusioned a lot of Ohioans on Reaganonmics, and the state re-elected its Democratic governor and senator easily, and Democrats generally ran very strong overall statewide. John Glenn was even beating Reagan in some polls. Then 1984 came along, and Reagan rolled up 59% of the vote.
Granted, this is not 1984 by any means, but it shows that a strong Democratic trend in Ohio did not produce a like result in the presidential race in the next cycle.
In '84, the recession had pretty much ended and people were feeling better about the economy. The "overhang" had receded somewhat. We're going to need something like that with Iraq in '08 to take the edge off a potential repudiation of Bush/Iraq vote in '08.
Another factor in '84 was the caliber of competition. People we just not that inclined to dump Reagan in favor of Mondale. Reagan was a personally popular incumbent going up against a candidate who was perceived as a holdover from a miserably failed Administration. 2008 will be a race for a completely open seat. Our candidate is going to have to present a positive message, because they won't have an incumbency to fall back on. And even if they did, they wouldn't want to, if it is that of the current Administration.