The terribly irony is that there are about as many people in Chicago proper as the rest of Illinois. So you got to win DeKalb, LaSalle, Kendall, Grundy, Kankakee, etc. by enough margin to offset whatever diff between Chicago vs. (real) Illinois.
Ryan would have won Il had his divorce records which were sealed miraculously not been unsealed. Not suprisingly Ryan was running against Obama and up significantly in the race.
A Republican CAN win Il, just like a Republican CAN win in PA.. its a different pattern to do it, but it can be done.