Potential Democratic Governor losses would be offset by probable wins in states like MD and IL. Also, MN is not going to flip.
Ill bet N is more likely to flip than IL or MD. Unless Lisa Madigan runs, Rauner will probably win in 2018. She cant run as long as Daddy is the House Speaker. He might retire by 2018 and then she can run.
Considering how much his approvals have already taken a nosedive, I'd guess no under most circumstances.
Pols who make tough decisions after see their approvals nose dive at the beginning of their terms. But they often win re-election. Walker, Snyder, Kasich.
Erlich in MD was defeated in the best Dem mid term election since 1986. If 2018 is another 2014 or 2010, Hogan will likely win.
You're forgetting that we are talking about Illinois. We're not Wisconsin, Michigan, or Ohio.