Doubt if Illinois can really be considered a part of the Midwest anymore
Then what is it? The only other region it's geographically somewhat close to is the South, which would make even less sense.
-Like West Virginia, I think Illinois isn't really part of any region. If I had to force every state into a region, Illinois would fall into the Midwest; West Virginia the South (though it's a lot less southern than KY, and really Appalachian). Of course, one can also force WV into the NE or Midwest, unlike IL, which can only fall in the Midwest.