All 118 Illinois House seats and 22 of 59 state Senate seats are on the ballot this fall. But because 52 House and 11 Senate races are uncontested, a handful of competitive districts — largely in the suburbs — will determine whether Democrats lose or add to their veto-proof majorities in both chambers. Democrats currently hold supermajorities of 74-44 in the House and 40-19 in the Senate, meaning Republicans would need a historic number of victories to take control of either chamber outright.