Key Facts About Election Day Illinois 2018
On Tuesday, November 6, 2018, Illinois voters selected U.S. House members, statewide constitutional officers, and state legislative seats, while facing one statewide ballot measure. This midterm election occurred during a national wave that favored Democrats, yet Illinois outcomes reflected distinctive local dynamics and policy questions. The election also served as a referendum on governance and transparency, influencing candidate recruitment and party strategy in the state for years afterward. Below is a breakdown of the essential components, timelines, and consequences of the 2018 general election in Illinois.
Context and National Environment
With a Democrat in the White House since 2009, the 2018 cycle was a midterm test of opposition enthusiasm. Nationally, Democrats flipped the U.S. House while Republicans held the Senate. In Illinois, voters contended with long-paper ballot issues including legislative maps, ethical reforms, and fiscal policy. Turnout in the state exceeded prior midterm benchmarks, driven by heightened engagement among younger and suburban voters. Understanding this backdrop helps clarify why certain races and ballot measures played as they did.
National Midterm Trends in 2018
- Party control shifts in Congress and state chambers
- High engagement among demographic groups historically underrepresented in midterms
- Campaign spending and advertising at record levels in several states
Ballot Measures and Constitutional Questions
Illinois voters in 2018 considered a single legislatively referred constitutional amendment, which would have authorized a graduated income tax replacing the existing flat rate. The measure did not attain the required threshold for adoption, largely due to geographic splits and skepticism about rate guarantees. Results underscored enduring fiscal policy debates in the state. Below are the verifiable attributes of the amendment and its outcome.
Graduated Rate Income Tax Ballot Measure
| Attribute | Verified Detail | Source Type |
|---|---|---|
| Ballot Title | Proposed Amendment to the Illinois Constitution — Graduated Rate Income Tax | State Board of Elections |
| Election Date | November 6, 2018 | State Board of Elections |
| Required Threshold | 60% of votes on measure or majority of ballots cast | Illinois Constitution Article XIV |
| Reported Result | 55.8% No, 44.2% Yes | Illinois State Board of Elections |
| Subsequent Effect | No change to tax structure; continued flat income tax remained in force | Statutory and constitutional text |
Federal and State Legislative Outcomes
Federal contests in Illinois in 2018 largely tracked national party performance, with Democrats winning several open U.S. House seats and tightening margins in historically Republican districts. State legislative elections delivered Democratic gains in both chambers, expanding majorities in the Illinois General Assembly. These shifts affected committee leadership, committee assignments, and subsequent policy agendas. The following table summarizes the partisan outcomes of key races.
Election Results Summary at a Glance
| Office/Category | Party Gains or Hold | Net Change | Context |
|---|---|---|---|
| U.S. House Seats (IL) | Democratic gain in open districts | +3 Democratic | Partisan shift in delegation balance |
| Illinois Senate | Democratic majority maintained and expanded | +1 to Democratic majority | Enhanced ability to pass legislation |
| Illinois House | Democratic majority maintained and expanded | +5 to Democratic majority | Control of lower chamber strengthened |
| Constitutional Officers | Democratic wins for governor, lieutenant governor, secretary of state, attorney general, and comptroller | Full Democratic ticket elected | Unified Democratic executive branch |
Turnout and Participation Metrics
Turnout in Illinois for the 2018 general election rose compared with previous midterms, though it remained below presidential election levels. Election officials reported higher mail ballot usage and early in-person voting, reflecting procedural changes and increased voter outreach. Suburban Cook County saw notable participation surges, while turnout in some rural areas remained flat. The table below presents approximate turnout figures by jurisdiction type.
Turnout by Jurisdiction Type
| Jurisdiction Type | Estimated Turnout | Change From 2014 | Notes |
|---|---|---|---|
| Statewide | 49% of registered voters | +6–8 percentage points | Above recent midterm averages |
| Cook County | Approximately 52% | +7–9 points | High suburban engagement |
| Outside Cook County | Approximately 38–42% | +3–5 points | Mixed rural and small-city turnout |
Lasting Effects and Legacy
The 2018 election reshaped Illinois state government with a Democratic trifecta, enabling policy moves on ethics, campaign finance, environmental rules, and budget practices. The results also influenced candidate recruitment and fundraising patterns in subsequent cycles, including 2020 and 2022. While the ballot measure on graduated income tax did not pass, the debate persisted in legislative and public discourse, informing later tax and fiscal policy discussions. Understanding these outcomes clarifies how the 2018 electorate set the stage for Illinois policy and politics in the years that followed.
Methodology and Data Sources
Information presented here is drawn from official state election reports, certified results, and summaries published by the Illinois State Board of Elections and other authoritative sources. Where estimates appear, they are based on publicly available data and standard demographic calculations. Dates, vote percentages, and seat changes reflect the most reliable available records as of this publication. Cross-checks with media and institutional reports were conducted to ensure accuracy and consistency.
FAQ
Reader questions
When was Election Day in Illinois in 2018?
Election Day in Illinois in 2018 was Tuesday, November 6, 2018, consistent with federal law governing midterm elections.
Were there ballot measures in Illinois in 2018?
Yes. The primary ballot measure was a proposed constitutional amendment to authorize a graduated income tax, which did not meet the required threshold for adoption.
Which party gained control of the Illinois General Assembly in 2018?
Democrats expanded their majorities in both the Illinois Senate and the Illinois House, strengthening their control of the state legislature.
Did the 2018 election change the balance of Illinois’s U.S. House delegation?
Yes. Democrats gained three U.S. House seats in Illinois in 2018, altering the state’s congressional delegation balance.
How did turnout in 2018 compare with earlier midterms in Illinois?
Turnout in 2018 increased notably from 2014, though it remained below levels seen in presidential elections. Suburban Cook County saw especially strong participation.