The most surprising results come in the Cincinnatti area. Kerry lost by huge margins in the suburbs that suround Cincy (no shock here), but he also lost Hamilton County, the county that contains the city of Cincinnatti.
I think you may have the factor of in-state rivalry with Cleveland (and the rest of the industrial northeast). Early on, Cincinnati was the most important city in the state based on it being a river port. In 1870, Hamilton County had double the population of Cuyahoga County. By 1900, Cuyahoga had passed Hamilton, and by 1920 it almost had twice the population. Cleveland early in the 20th century was the 4th largest city in the country. The heavy industrialization made Cleveland naturally more Democratic, and Cincinnati may have tended to be more Republican in reaction. The Tafts are also from Cincinnati.
