What makes Indiana Southern?
Though Southern Missouri, Illinois and Indiana are all culturally Southern (IMO), there is no way in hell that the state of Indiana is part of the South. It might have a few more Southern influences (even my sister living in Indianapolis says it is noticably more influenced by the South than Iowa), but it's clearly a Midwestern state.
This may sound crazy, but there are people who think that Wisconsin has more in common with the South politically and even culturally than with the rest of the Midwest. There might be a grain of truth to this claim, but it's obviously an exaggeration.