2010Flipped from DemocraticFinal resultsIncumbent defeated
2010 election for Illinois Representative District 66
Illinois House of Representatives · Illinois
David Harris (R) won with 54.0% of the vote, defeating Mark Walker (D) by 8.0 points, a seat Democrats won last time.
David HarrisRepublican · winner
54.0%16,147
Mark WalkerDemocrat · incumbent
46.0%13,763
29,910 votes
Source: Harvard Dataverse / Carl KlarnerUpdated Sep 30, 2026, 7:29 AM ET
The seat over time
D − R margin in this seat's races around 2010
Races before and after
Source: Harvard Dataverse / Carl KlarnerUpdated Sep 30, 2026, 7:29 AM ET