Bleh, that's crap about Florida. While, yes, native Foridian drivers are bad and should be on the list....they're not the worst. Florida just seems so bad because all the crappy drivers from everywhere else come to Florida, rent a car, don't know where the hell they're going and try to make a 3-lane left turn into someone else's side when they realize they're about to miss it.
I would personally vote for Pennsylvania because I have NEVER seen people come to a STOP and the end of the ON-ramp for a major interstate, when it's not busy, and look bot ways as if they were making a left turn (this occured several times in the one day I was there). Also, they're slow, don't use their turns signals, ride the left lane, and all-around suck.
Illinois drivers aren't bad....they're just all jerks.