Dold's loss had nothing to do with Kirk and everything to do with Democrats in the district going to vote. It is a Democratic district that, while Dold has run, has had a big % of ticket-splitters.
You can only push that so far before the Republican falls off. Clinton was the overwhelming favorite in the district - correct me if I am wrong, but her margin in Lake County (20pts) was greater than any Democrat ever (Obama netted 19.5 pts in '08).
While Trump performed better than expected in some suburban areas (see Milwaukee), he may have performed even worse than expected in the Chicago suburbs. Dismal - lost DuPage County by 14 points. You couldn't have rationally predicted a worse performance in the area.
Trump was the worst candidate in decades in the Milwaukee suburbs. His underperformance there was the only reason the state was as close as it was.
