Ohio is officially counted as the eastern most Midwestern state. It has been for at least a century.

I see the Midwest as more of a cultural region than a physical one. Ohio and Indiana honestly both perfectly fit in with the Midwestern culture, so I welcome them into the "Midwestern" moniker

Personally, I see the Midwest as a triangle with Ohio, Minnesota, and Missouri as the corners. Kentucky and Arkansas are too southern culturally (and honestly, the southern half of Missouri is too) Oklahoma is almost southwestern culturally, and Kansas, the Dakotas and Nebraska are very western culturally (and honestly Western Minnesota and Western Iowa are pretty Western culturally too)