It's been a while since I posed one of these political-sociological questions, but I think Indiana really cries out for it. A lot of my colleagues are down on Obama's chances there because they assume it's demographically similar to Ohio, where working-class whites never really took to him.
My own feeling is that Indiana should be a lot more favorable to Obama, all things being equal. In addition to bordering Illinois, it's kind of a mix of Farm Belt and Rust Belt, as opposed to mostly Rust Belt like Ohio. Thus far in the campaign, Farm Belt states, like those of the Upper Midwest, have been much, much more, er, fertile for Obama.
I've speculated (see here and here) that this has to do with them being more progressive racially, which itself has to do with their unusually small African American populations, and with them being settled more by Northern Europeans (Germans, Scandinavians, etc.) than Southern and Eastern Europeans (and maybe Scots-Irish). But this is all very crude and ill-informed. If anyone has any further sociological insights, by all means let me know.