There's not a lot that a state legislative candidate can do when his or her party's presidential nominee starts to tank.
The presidential race drives turnout to the point where down-ballot candidates must struggle mightily to rise above the noise and get their messages heard by distracted voters.
And because there are no statewide races in Illinois this year, that means there are no truly high-profile campaigns to "break up" any presidential advantage or momentum. Congressional races are all that state legislators have now to cushion the blow from the top, and down-ballot candidates are increasingly pinning their hopes on those contests.