At this point, the race between Hillary and Barack is 49% style, 49% self-identification, and 2% substance. I believe that Hillary Clinton's style and connection to the Bill Clinton presidency puts her at an advantage in certain states while Barack Obama's style and his race puts him at advantage in other states. Below is why I think Barack will win in Ohio.
Style
Hillary supporters want a fighter while Barack supporters want someone to transcend politics. New Jersey, New York, and Massachusetts went for Hillary because these people (and I grew up in NJ so I'm one of them) like an angry politician. They don't care if their politicians are investigated and impeached and part of a party "machine" as long as they get the job done at the end of the day (in fact they expect it, because corruption often gets things done). Southern California (my current home), the CA central Valley, Las Vegas, NV, and Southern Florida is full of people with similar attitudes.
Contrast this with younger more educated voters who see grave problems in the world and want a transformational candidate (Connecticut and Washingon). Midwesterners aren't necessarily looking for that kind of quality, but they really don't like outwardly angry candidates (I lived in western PA and folks there were really turned off by conflict). Personally, I don't think that Hillary is angry, but I think midwesterners think she is.
Self-Identification
Barack is drawing an overwhelming number of support from African Americans, while Hillary is drawing the majority of the Latino vote. I truly believe that Clinton won Florida, California, and Arizona because of race while Barack won Georgia, Alabama, and Louisiana because of race.
In short, Hillary wins states dominated by big, old cities and Latinos while Barack wins rural states, states with new cities and states with a preponderance of African-Americans.
Testing the Model
I believe that my model predicts why Hillary Clinton won NH, MA, NY, NJ, MI, FL, AZ, NV & CA and why Barack Obama won ME, CT, GA, AL, LA, MO, KS, NE, ND, ID, UT, WA, & AK. It does not do as well predicting why Barack won DE and tied NM or why Hillary won OK & TN (she won AS because it's her home state). Having said that, no model is perfect, and my point is to look at Ohio, so lets go...
Ohio
Ohio is a midwestern state, and midwesterners don't like divisiveness. Second, there are more African Americans in Ohio than Latinos. Like Delaware and Connecticut, the populace is more educated than the nation as a whole (due to the role Ohio played on the Underground Railroad, many of the African Americans are highly educated).
It is true that Ohio has some crumbling cities whose whites tend to to trend to Hillary. However, Cleveland and Columbus both have major Univiersities, which means a younger electorate. Contrast this with Detroit, Michigan which does not have any major universities.
All of these qualities point to a Barack win in Ohio.
Other States
Based on my analysis of these candidates, Hillary should win Texas (less educated, more Latinos) and Wisconsin (More of an industrial economy, very few African Americans). Of course, Every Obama win makes a future Obama win more likely and it is possible that he wins those states. I would however, be willing to bet that WI and TX are Hillary's best states in the next two months.