The Illinois State Senate is the upper chamber of the Illinois General Assembly. Alongside the Illinois House of Representatives, it forms the legislative branch of the Illinois state government and works alongside the governor of Illinois to create laws and establish a state budget. Legislative authority and responsibilities of the Illinois State Senate include passing bills on public policy matters, setting levels for state spending, raising and lowering taxes, and voting to uphold or override gubernatorial vetoes.
The Illinois State Senate meets in the state capitol building in Springfield, Illinois.
Twenty of the Illinois State Senate's 59 seats were up for election in 2024. The chamber's Democratic supermajority remained 40-19.
All 59 seats in the Illinois State Senate were up for election in 2022. The chamber's Democratic supermajority decreased from 41-18 to 40-19.
Illinois has a Democratic trifecta. The Democratic Party controls the office of governor and both chambers of the state legislature.
This page contains the following information on the Illinois State Senate.
Article IV of the Illinois Constitution states: "To be eligible to serve as a member of the General Assembly, a person must be a United States citizen, at least 21 years old, and for the two years preceding his election or appointment a resident of the district which he is to represent."[4]
Democrats won control of the Illinois State Senate in 2002. In 2024, they won a 40-19 majority.
The table below shows the partisan history of the Illinois Senate following every general election from 1992 to 2024. All data from 2006 or earlier comes from Michael Dubin's Party Affiliations in the State Legislatures (McFarland Press, 2007). Data after 2006 was compiled by Ballotpedia staff.
A state government trifecta is a term that describes single party government, when one political party holds the governor's office and has majorities in both chambers of the legislature in a state government. Between 1992 and 2023, Illinois was under the following types of trifecta control:
Illinois Party Control: 1992-2025 Nineteen years of Democratic trifectas • Two years of Republican trifectas Scroll left and right on the table below to view more years.
Under the Illinois Constitution of 1970, senators are divided into three groups, each group having a two-year term at a different part of the decade between censuses, with the rest of the decade being taken up by two four-year terms. Depending on the election year, roughly ⅓, ⅔, or all of the senate seats may have terms ending.[5] Illinois holds elections for its legislature in even years.
Elections for the Illinois State Senate took place in 2022. The general election was on November 8, 2022. A primary was scheduled for June 28, 2022. The filing deadline was March 14, 2022.
In the 2022 elections, Democrats lost one net seat, decreasing their majority to 40-19. On December 9, 2022, former State Sen. Scott Bennett, who won his former seat, died due to complications of a brain tumor. In January 2023, State Sen. Jason Barickman resigned. These vacancies are not reflected on the chart below.
Elections for the office of Illinois State Senate took place in 2020. The general election was held on November 3, 2020. A primary was scheduled for March 17, 2020. The filing deadline was December 2, 2019.
In the 2020 elections, Democrats increased their majority in the Illinois State Senate from 40–19 to 41–18.
Elections for the Illinois State Senate took place in 2018. An open primary election took place on March 20, 2018. The general election was held on November 6, 2018. The candidate filing deadline was December 4, 2017.[6]
In the 2018 elections, Democrats increased their majority in the Illinois State Senate from 37-22 to 40-19.
Elections for the Illinois State Senate were held in 2016. The primary election was held on March 15, 2016, and the general election was held on November 8, 2016. The candidate filing deadline was November 30, 2015.[7] A total of 40 seats out of the 59 seats in the Illinois State Senate were up for election in 2016.
Heading into the election, Democrats held a 39-20 majority. Democrats lost two seats in the election, giving them a 37-22 majority.
Elections for the Illinois State Senate took place in 2014. A primary election took place on March 18, 2014. The general election was held on November 4, 2014. The signature filing deadline for candidates wishing to run in this election was December 2, 2013. A total of 19 seats out of the chamber's 59 seats were up for election in 2014.
Heading into the election, Democrats held a 40-19 majority. Democrats lost one seat in the election, giving them a 39-20 majority.
Elections for the office of Illinois State Senate took place in 2012. The primary election was held on March 20, 2012, and the general election was held on November 6, 2012. The candidate filing deadline was December 5, 2011. All 59 seats were up for election, as the election was the first following redistricting.
Heading into the election, Democrats held a 35-24 majority. Democrats gained five seats in the election, giving them a 40-19 majority.
Elections for the office of Illinois State Senate took place in 2010. The primary election was held on February 2, 2010, and the general election was held on November 2, 2010. The candidate filing deadline was November 2, 2009.
Heading into the election, Democrats held a 37-22 majority. Democrats lost two seats in the election, giving them a 35-23 majority with one vacancy.
If there is a vacancy in the Illinois General Assembly, the state constitution mandates that the seat must be filled by appointment when allowed by law. The appointment must be made within 30 days after the vacancy. If a vacancy occurs in the Senate with more than twenty-eight months remaining in the term, the appointment is interim until the next general election, when a special election must be held. All other House and Senate vacancies are to be filled by an appointment from the same political party that last held the seat.[14] If the vacated seat was held by an independent (no party affiliation), the governor is to appoint an independent successor within 30 days.[15]
The vacancy must be filled by the respective party organizations covering the legislative district.[16] The respective committeemen and committeewomen representing the legislative district must vote on a replacement.[17] The person selected for the seat serves for the remainder of the unfilled term.[18]
The Illinois General Assembly is responsible for drawing both congressional and state legislative district lines. Both chambers of the state legislature must approve a redistricting plan. The governor may veto the lines drawn by the state legislature.[19]
In the event that both chambers of the state legislature do not approve a legislative redistricting plan, a backup commission must draw the lines. The majority and minority leaders of each chamber must appoint two members each to the commission (one legislator and one general citizen). Of the eight commission members, no more than four may belong to the same political party. In the event that these eight members cannot approve a plan, the Illinois Supreme Court must select two individuals (from different political parties) as potential tiebreakers. The secretary of state must then appoint one of these individuals to the backup commission to break the tie.[19]
The Illinois Constitution requires that state legislative districts be "contiguous and reasonably compact." There are no such requirements in place for the state's congressional districts.[19]
State law also mandates the establishment of state legislative districts "that allow racial or language minority communities to elect--or influence the election of--the candidates of their choice, even if no comparable district would be required by the federal Voting Rights Act."[19]
The Illinois State Legislature approved new state legislative maps in a special session on August 31, 2021. Gov. J.B. Pritzker (D) signed the new maps into law on September 24, 2021.[20] These maps were revised versions of maps enacted on June 4, 2021, that the legislature based on non-census population estimates. Following the release of census data in August, the legislature reconvened to develop and approve a revised map. These maps were later subject to a federal lawsuit that was decided on December 30, 2021, with the court upholding the maps enacted on September 24, 2021.[21] Learn more here.
District map before and after 2020 redistricting[edit]
Below is the state Senate map in effect before and after the 2020 redistricting cycle.
Illinois State Senate Districts until January 10, 2023
Click a district to compare boundaries.
Illinois State Senate Districts starting January 11, 2023
Following the completion of the 2010 United States Census, Illinois lost one congressional seat. At the time of redistricting, Democrats held majorities in both chambers of the state legislature. On May 30, 2011, the Illinois House of Representatives approved a congressional redistricting plan. The Illinois State Senate approved the plan on May 31, 2011, and Governor Pat Quinn (D) signed it into law on June 24, 2011. Legal suits were filed challenging the new congressional district map, but these were all ultimately dismissed.[19][22][23]
The state legislative redistricting plan was passed by the legislature on May 27, 2011. Quinn signed the map into law on June 3, 2011. As with the congressional map, lawsuits were filed challenging the new state legislative districts. These suits were ultimately dismissed.[19]
The legislation tracker below displays all legislation that the Illinois State Senate has approved in its most recent legislative session—this includes legislation that has been sent from the Senate to the House and legislation that has already been approved by both chambers and signed by the governor. The table below includes the bill number, its name, progress, most recent action date, and sponsor. Scroll up and down and side to side to see more. Click the bill number to read the bill text and see its voting history. Click the headings to sort the content. Rearrange the order of the headings by clicking and dragging them. Click the magnifying glass in the bottom left corner to search for specific terms. The legislation tracker is maintained and updated by BillTrack50.
Dates of legislative sessions in Illinois by year[edit]
Select a topic from the dropdown below to learn more.
Several state legislatures had their sessions impacted as a result of the 2020 coronavirus pandemic. The Illinois General Assembly suspended its session, effective March 16, 2020. The suspension was originally set to expire the week of March 23, 2020. It was subsequently extended. The legislature reconvened on May 20, 2020, before adjourning on May 23, 2020.[24][25][26][27][28][29]
In 2018, the legislature was in session from January 8, 2018, through May 31, 2018. To read about notable events and legislation from this session, click here.
In 2017, the legislature was in session from January 11, 2017, through May 31, 2017. The legislature held its first special session from June 21, 2017, to July 6, 2017. The legislature held its second special session from July 26, 2017, to July 31, 2017. The state Senate met on August 13, 2017, to override Gov. Bruce Rauner's (R) veto of a school funding formula. The state House met on August 16, but did not override the veto. The Illinois state Legislature met again from August 28 to August 29 in special session over school funding. The legislature held a veto session from October 24 to November 9.
Click [show] to read about the 2017 Illinois budget debates.
In 2017, disagreements between Governor Bruce Rauner (R) and the Democratic-controlled Illinois General Assembly over the state budget drew national attention when S&P Global Inc. and Moody’s Investors Service downgraded Illinois' credit rating and some government services, including transportation projects and the state lottery, were on the verge of being shut down.[30][31] Rauner and the legislature failed to come to an agreement on a budget during the regular session, which ended on May 31, leading Rauner to call a special session from June 21 to June 30, the last day of the 2017 fiscal year. A budget agreement was not reached before June 30, meaning Illinois entered the 2018 fiscal year without a budget.
A budget was passed on July 6, 2017, when the legislature overrode Rauner's vetoes of a $36 billion spending plan and a $5 billion tax increase. In the votes in the Illinois House, 10 Republicans joined the Democrats in voting for the overrides. Up to this point, Illinois had not passed a budget since 2014, when Pat Quinn (D) served as governor. According to The Associated Press, two years was the longest any state had gone without a budget in recent memory.[32]
Important issues surrounding the budget debate included differences in Democratic and Republican plans concerning income tax rate increases, a property tax freeze, changes to regulations related to injured worker compensation, and the state's pension liabilities. The budget deal that eventually passed increased the personal income tax rate from 3.75 to 4.95 percent, increased the corporate tax rate from 5.25 to 7 percent, and left overall spending at $36 billion for fiscal year 2018.[33]
The budget had an impact beyond the state, costing Wisconsin millions from its state budget. This was because, as of July 2017, Illinois and Wisconsin had a reciprocity agreement to account for the greater number of Wisconsinites that cross the state border to work in Illinois, but not pay state income taxes, than Illinoisans who came to work in Wisconsin. With higher incomes taxes in Illinois, Wisconsin's reciprocity payment increased.[34]
Coverage of the budget negotiations centered on the relationship between Rauner and Speaker of the House Michael Madigan (D).[35] As of July 6, 2017, Rauner was seeking re-election as governor in 2018 and Madigan was defending the Democrats' 67-51 majority in the state house. Rauner and Madigan disagreed on a number of issues including whether the income tax increases should have been permanent.[36]
$8.2 billion in state aid for public schools was included in the budget agreement. However, language was also included that said $6.76 billion of the aid had to be dispersed through a funding formula that calculated state aid for school districts based on the cost of strategies that supporters say are proven to improve student performance. The funding for districts could be increased by elements such as income, property wealth, and English-learning needs.[37][38][39]On August 29, the Illinois General Assembly passed a bill that included the necessary funding formula. Read more the timeline of events below.
On May 31, the Legislature passed SB 1, which contained the necessary funding formula. Gov. Rauner indicated that he would veto the bill, causing Senate President John Cullerton (D) to hold it in the chamber.[40] According to Rauner's office, the governor would not support the bill because he believed it would benefit Chicago at the expense of other areas of the state.[41]
On July 24, Rauner called the General Assembly into a special session starting July 26 to address education funding. He had set a deadline of 12:00pm CT on July 24 for Cullerton to send him SB 1 so that he could use his amendatory veto power to make unspecified changes to the provisions he disagreed with. When the deadline passed without Cullerton sending him the bill, he called the special session.[42] On July 31, the last day of the special session, SB 1 was transmitted to Rauner.[43]
Rauner issued an amendatory veto on August 1, rewriting SB 1 to remove a $250 million block grant to Chicago Public Schools and changing how the funding formula determines state aid.[44] According to the Illinois State Board of Education, Rauner's changes would result in a $463 million decrease in funding for Chicago Public Schools in the 2017-2018 school year.[45] The Illinois Senate met on August 13 and overrode the veto by a 38-19 vote, with all Democrats and Republican Sam McCann voting to override.[46] The Illinois House was scheduled to vote on the override on August 23, but Speaker Madigan cancelled the vote on August 22. He said that progress had been made in negotiations with Rauner and Republicans.[47][48][49]
On August 24, the four leaders in the General Assembly— Madigan, Cullerton, Senate Minority Leader Bill Brady (R), and House Minority Leader Jim Durkin (R)— announced that they had reached a compromise agreement on SB 1. According to Politico, the agreement kept the funding formula from SB 1 and included $75 million in subsidies for private school education.[50] On August 28, 2017, the Illinois House rejected the agreement in a 46-61 vote.[51] The chamber next voted on an override of SB 1. After the override vote received just 63 of the 71 votes it needed to pass, the chamber took up the compromise bill again and passed it 73-34.[52] On August 29, the Illinois Senate passed the compromise bill by a 38-13 vote.[53] Gov. Rauner signed the bill into law on August 31.[54]
According to The Chicago Sun-Times, some schools in low-income areas cannot remain open without the state money that is allocated by the budget.[37] In addition to the state aid in the budget, education funding in Illinois also comes from property taxes levied by local governments. Areas that pay more in property taxes can spend more on schools and are less dependent on state aid.[55]
Major issues during the 2015 legislative session included a potential income tax increase, a statewide minimum wage and federal healthcare funding.[57]
Major issues during the 2014 legislative session included the pending expiration of a temporary income tax, corporate tax incentives, Chicago pension reform, and capital construction.[58]
Major issues during the 2013 legislative session included regulation of horizontal hydraulic fracturing, concealed carry, same-sex marriage, and pension reform.[59][60][61][62]
In 2011, the General Assembly was in session from January 12-June 1. A special session was called by Governor Pat Quinn (D) to settle disputes regarding Illinois construction projects on June 22, 2011.[63]
The Tenth Amendment of the U.S. Constitution declares that any power not already given to the federal government is reserved to the states and the people.[64] State governments across the country use this authority to hold legislative sessions where a state's elected representatives meet for a period of time to draft and vote on legislation and set state policies on issues such as taxation, education, and government spending. The different types of legislation passed by a legislature may include resolutions, legislatively referred constitutional amendments, and bills that become law.
Article IV of the Illinois Constitution establishes when the Illinois General Assembly, of which the Senate is a part, is to be in session. Section 5 of Article IV states that the General Assembly will convene its regular session on the second Wednesday of January.
Section 5 also creates rules for the convening of special sessions. The section allows the Governor of Illinois to convene the General Assembly or the Senate alone. When the Governor calls a special session, the General Assembly can generally only deal with matters related to the purpose of the session, as stated by the Governor's proclamation of the session, but they can also deal with impeachments or confirmation of appointments. Section 5 also allows the presiding officers of both houses of the General Assembly to convene a special session through joint proclamation.
State legislatures can override governors' vetoes. Depending on the state, this can be done during the regular legislative session, in a special session following the adjournment of the regular session, or during the next legislative session. The rules for legislative overrides of gubernatorial vetoes in Illinois are listed below.
How many legislators are required to vote for an override? Three-fifths of members in both chambers.
Three fifths of members in both chambers must vote to override a veto, which is 71 of the 118 members in the Illinois House of Representatives and 36 of the 59 members in the Illinois State Senate. Illinois is one of seven states that requires a three-fifths vote from both of its legislative chambers to override a veto.
Are there other special rules?
If the governor uses the line item veto to reduce an appropriation, that reduction can be overturned by a majority vote in both chambers.
"The house to which a bill is returned shall immediately enter the Governor's objections upon its journal. If within 15 calendar days after such entry that house by a record vote of three-fifths of the members elected passes the bill, it shall be delivered immediately to the second house. If within 15 calendar days after such delivery the second house by a record vote of three-fifths of the members elected passes the bill, it shall become law."
Every state legislature and state legislative chamber in the country contains several legislative committees. These committees are responsible for studying, amending, and voting on legislation before it reaches the floor of a chamber for a full vote. The different types of committees include standing committees, select or special, and joint.
Standing committees are generally permanent committees, the names of which sometimes change from session to session.
Select or special committees are temporary committees formed to deal with specific issues such as recent legislation, major public policy or proposals, or investigations.
Joint committees are committees that feature members of both chambers of a legislature.
Ballotpedia covers standing and joint committees. The Illinois State Senate has 30 standing committees:
The Illinois Constitution provides four mechanisms for amending the state constitution—a constitutional convention, a legislative process, and a citizen-initiated process.
In Illinois, the number of signatures required for an initiated constitutional amendment is equal to 8% of votes cast for governor in the previous gubernatorial election. Initiated measures in Illinois may only amend Article IV of the Illinois Constitution, which addresses the structure of the Illinois State Legislature. All amendments must be approved by either a majority of those voting in the election or three-fifths of those voting on the amendment itself.
According to Article XVI, the state Legislature can refer constitutional amendments to the ballot for voters to decide.
A 60% vote is required during one legislative session for the Illinois General Assembly to place a constitutional amendment on the ballot. That amounts to a minimum of 71 votes in the Illinois House of Representatives and 36 votes in the Illinois State Senate, assuming no vacancies. Amendments do not require the governor's signature to be referred to the ballot.
According to Article XIV of the Illinois Constitution, a question about whether to hold a constitutional convention is to automatically appear on the state's ballot every 20 years starting in 1918. Illinois is one of 14 states that provides for an automatic constitutional convention question. A constitutional convention question can also be placed before the state's voters if 60% of the members of both houses of the Illinois General Assembly vote in the affirmative. If such a question does appear on the ballot, it must be affirmed by a supermajority vote of 60% of those voting on the question or a majority of those who cast a ballot for any office in that election.
The table below shows the last and next constitutional convention question election years:
The following measures have been certified for the ballot.
No measures to list
Potential:
The following measures have made it through one chamber—or one session for two session states—and may appear on the ballot in 2026.
No measures to list
2025 measures:
Below is a list of measures that were referred to the 2025 ballot by the legislature or that have made it approximately halfway through the process in the legislature for referral to the ballot in 2025.
↑Under the Illinois Constitution of 1970, senators are divided into three groups, each group having a two-year term at a different part of the decade between censuses, with the rest of the decade being taken up by two four-year terms. Depending on the election year, roughly ⅓, ⅔, or all of the senate seats may have terms ending.