Illinois Democrats Gain Largest Majority in Decades
Democrats are expected to hold nearly three-fourths of the seats in the Illinois General Assembly when the next session begins in January, according to projections following the November 3 general election. If those projections hold, the party will have its largest share of the legislature in at least 60 years, further reducing Republican representation in a state government Democrats already control.
Projected results show Democrats winning 45 of the 59 seats in the Illinois Senate and 84 of the 118 seats in the Illinois House of Representatives. Republicans would hold the remaining 14 Senate seats and 34 House seats, giving Democrats a 129-to-48 advantage across both chambers. That works out to about 76.3% of the Senate and 71.2% of the House, or 72.9% of the General Assembly overall, compared with 27.1% for Republicans.
Democrats entered the election with 40 Senate seats and 78 House seats, or about two-thirds of the legislature. That was already more than the three-fifths majority needed to override a governor’s veto. The projected gain of five Senate seats and six House seats would raise the party’s share by more than six percentage points and leave Republicans with fewer than three of every 10 seats. As long as Democrats vote together, Republicans will have little ability to influence legislation, state spending or other decisions that require approval from the General Assembly.
Results at the top of the ballot added to the difficulties for Republican legislative candidates. Gov. JB Pritzker won reelection with about 59.8% of the statewide vote, while Republican nominee Darren Bailey received about 36.8%, a margin of roughly 23 percentage points. Pritzker’s support was not limited to Cook County. He received enough votes in the rest of the state that he would have defeated Bailey even without Cook County’s results, which points to the broader trouble Republicans have had competing statewide, including in areas outside Chicago and its suburbs.
The projected majority would be larger than any recorded in the General Assembly’s published partisan division records, which cover elections from 1962 through 2024. Because the legislature has not always been the same size, percentages offer a more consistent comparison than seat counts. Until 1983, the House had 177 members. The Cutback Amendment, passed in 1980, ended cumulative voting and reduced the number of representatives elected from each district, bringing the House to its current 118 members.
Those records show Democratic control growing steadily over the past several decades. After the 1982 election, Democrats held 70 House seats and 33 Senate seats, or about 58.2% of the General Assembly. Following the 1990 election, they held 72 House seats and 31 Senate seats, keeping the same overall share. The party’s advantage grew in the 2000s and 2010s. Democrats won 71 House seats and 40 Senate seats in 2012, or 62.7% of the legislature, and 74 House seats and 40 Senate seats in 2018, or 64.4%. After the 2022 election, they held 78 House seats and 40 Senate seats, about 66.7% of the total, and that balance did not change after the 2024 election.
The latest gains came under legislative maps that Democrats drew after the 2020 census. In 2021, the party used its control of the General Assembly and the governor’s office to approve new district boundaries without Republican support. The maps were first used in 2022 and remain in effect for the 2026 election. Republicans and voting rights advocates have criticized the districts as gerrymandered to favor Democratic candidates and limit Republican chances of winning legislative seats. Democratic lawmakers have defended the redistricting process, while Republicans argue the maps have helped keep their party in the minority in Springfield.
