Ohio might well be the worst state for astronomy in general, but the award for worst astronomy weather should likely go to West Virginia: it is the cloudiest state in the continental U.S., due the effectiveness of the Appalachain Mountains in trapping cloudiness on the western, windward side of their range. Of course, all that cloudiness is mitigated (to a fairly small degree, in my opinion) by the generally low levels of light pollution in the state.
If you look at the National Climate Data Center's data for # clear days / year, the worst location appears to be Elkins, WV, just west of the spine of the Appalachian Mountains. One of the reasons for Elkins being so bad is the fog that's a big, big problem on any night where the breeze dies down. Going up higher in the mountains helps cut down on fog, but you'll get more orographic (upslope) clouds, so it's largely a wash.
One thing to remember is that it's not the # clear days that matters, but the amount of clear NIGHTS. Most of NOAA's sky cover data relates to daytime conditions only. I've attached a photo from a previous post that shows avg. long-term nighttime cloud cover since 2000 in the northeastern U.S., c/o NASA's Goddard Space Flight Center / Giovanni online data.
As far as what the worst state East of the Mississippi is for stargazing, you could also make a case for Michigan, as you've got (a) lots of clouds, but also (b) ridiculously-long summer twilight and little true-dark time in the warm season, and © they're still clinging to the Eastern Time Zone, which helps make sunset and the arrival of truly dark skies ridiculously late as well.
Since 75W is the standard meridian for the Eastern Time Zone, anything west of 82.5W should be in the Central Time Zone. Thus, Michigan, Indiana, Kentucky and Tennessee should entirely be in the Central Time Zone. That alone would improve these states' ratings among stargazers. It won't help the weather, but it at least will be getting dark an hour earlier.