I have issues with a Rauner nomination since I feel like eventually the delegates would support a more conservative candidate, and also becuase I strongly doubt even Rauner could survive in a blue year like 2018 in a state as liberal as Illinois. If he did, though, and then won the nomination, I'd say he loses the general election because ultra conservative Republicans stay home or vote for a third-party or write-in candidate rather than Rauner. Maybe some right-wing third-party alternative would crop up (the Constitutionalist candidate? I don't know) which enough far right-wingers would back for Clinton to win by a comfortable amount (north of 300 electoral votes and a popular vote win of about 5 points or so).
In this timeline, 2018 would have a Hillary midterm, and I don't see her being popular enough to stop another red wave (presumably Hillary got narrow majorities in both chambers)
