Actually, Kenyon has more students from New England and the Mid-Atlantic states than from the entire Midwest. The kids do come from all over, the vast majority would have been Kerry supporters, and they all knew Ohio was a far more important state than their home states.
There are technical rules for residency, but generally speaking you can declare residency in any one particular place and nobody complains if you're consistent. College students, who pay very few taxes and own no property, have very little problem declaring residency wherever they want. It would be interesting to see if any of them voted in two places, though.