The campaign hasn't even really started here yet. Once the commercials start and the volunteers mobilize, Quinn will get a boost. A lot of those Rauner voters are Democrats who don't like Quinn but will switch their vote when they find out about who Rauner is.
I doubt it. If Brady only lost by 1 (and he's the worst candidate for Illinois) and Quinn has gotten more unpopular since, then I think Rauner has a good shot.
It was also the best year for the GOP since 1994 and the GOP picked up the Senate seat that year, so I would by no means count Quinn out. The Cook County machine may not be enough to eke it out this time, though.