Short Answer

Juliana Stratton is expected to win the 2026 Illinois U.S. Senate election as the Democratic nominee, succeeding retiring incumbent Dick Durbin, with the market pricing this outcome at 97.1%.

1. Market Behavior & Drivers

This market's low probability for a Republican victory reflects Illinois's established Democratic lean. The general election matchup is set between Democrat Juliana Stratton, the current Lieutenant Governor, and Republican Don Tracy, a former state party chair. Incumbent Democrat Dick Durbin's earlier announcement that he would not seek re-election opened the seat but did not fundamentally alter the partisan dynamics of the race.
The price action in this market is not correlated with any reported news or polling data. Total traded volume is exceptionally low at just 114 contracts. The fluctuations from a high of 4.9% to a low of 1.1% are therefore likely a product of market illiquidity rather than a reaction to specific events. In such a thinly traded environment, small orders can create significant price swings without representing a meaningful shift in perceived odds.
  • Since last update (~28d): Don Tracy's model and market probabilities both increased by 0.7pp, reflecting a market-led move.
  • Our overall confidence score significantly strengthened, increasing by 3.0pp from 5.0 to 8.0.
  • Juliana Stratton's model probability decreased by 0.7pp, with the market declining 0.6pp.
  • Democratic nominee Juliana Stratton is the heavy favorite in "Solid Democratic" Illinois.
  • Stratton holds a significant fundraising advantage over Republican Don Tracy.

Who Wins and Why

Outcome Market Model Why
Don Tracy 3.1% 3.1% Don Tracy faces an uphill battle in a Solid Democratic state and trails significantly in fundraising.
Juliana Stratton 97.1% 96.9% Juliana Stratton is the heavy favorite in a Solid Democratic state and holds a significant fundraising advantage.

Current Context

The 2026 U.S. Senate election in Illinois is scheduled for November 3, 2026. This election will fill the Class II seat currently held by incumbent Dick Durbin (D), who announced on April 23, 2025, that he would not seek re-election [1][2]. Democrat Juliana Stratton won the March 17, 2026, Democratic primary [1]. The general election candidates are Democrat Juliana Stratton, the current Lieutenant Governor, and Republican Don Tracy, a former Illinois Republican Party chair [3][1][2]. As of September 9, 2026, the election winner has not yet been determined [1].
Juliana Stratton is strongly favored in election forecasts. Prediction markets and election forecasts consistently rate the race as Solid Democratic, with Juliana Stratton holding a 94%–98% probability of winning as of early September 2026 [3][4][5][6]. Campaign finance reports show Stratton raised approximately $5.91 million by June 30, 2026. Don Tracy's campaign raised $2.46 million during the same period [3][5][7].
Sources (7)
  1. 1United States Senate election in Illinois, 2026 - Ballotpediaballotpedia.org
  2. 2Illinois U.S. Senate Election 2026: Latest Polls - The New York Timesnytimes.com
  3. 32026 Illinois US Senate Forecastvotes.decisiondeskhq.com
  4. 42026 Illinois Senate Election: Polls & Odds | Prediction Edgepredictionedge.com
  5. 5Illinois — U.S. Senate — 2026 forecast — Akashicakashic.app
  6. 6Illinois Senate Election Winner Predictions & Odds 2026 | Polymarketpolymarket.com
  7. 7Will a Democrat Win the 2026 Illinois Senate Race?lines.com

2. Price Chart

Historical Price (Probability)

Outcome probability
Date

3. Market Data

Contract Snapshot

This market resolves "Yes" if Juliana Stratton, the Democratic candidate, wins the Illinois Senate race, and "No" if she does not. The outcome is determined by which party's candidate ultimately wins the seat. Trading for this market begins on November 3, 8:00 AM EST, with a maximum payout date of November 3, 2027.

Available Contracts

Market options and current pricing

Outcome bucket Yes (price) No (price) Last trade probability
Juliana Stratton $0.98 $0.03 97%
Don Tracy $0.03 $0.99 3%

Market Discussion

The 2026 Illinois U.S. Senate general election is scheduled for November 3, 2026, and has not yet taken place as of September 9, 2026 [1][2][3][4][5]. Lieutenant Governor Juliana Stratton (D) won the primary election on March 17, 2026, and will face Republican nominee Don Tracy [1][2][3][5][6]. Prediction markets and forecasting models overwhelmingly favor Stratton to win, with win probabilities consistently cited between 96% and 98% as of early September 2026 [4][7][8].

Sources (8)
  1. 1Stratton defeats Krishnamoorthi with help from Chicago, downstate voters | NPR Illinoisnprillinois.org
  2. 2Juliana Stratton wins Illinois Senate Democratic primary election racenbcnews.com
  3. 32026 United States Senate election in Illinois - Wikipediaen.wikipedia.org
  4. 42026 Illinois US Senate Forecastvotes.decisiondeskhq.com
  5. 5United States Senate election in Illinois, 2026 - Ballotpediaballotpedia.org
  6. 62026 Illinois US Senate Live Election Results | DDHQvotes.decisiondeskhq.com
  7. 72026 Illinois Senate race — polls, candidates & voter guide — IJRijr.com
  8. 82026 Illinois Senate Election: Polls & Odds | Prediction Edgepredictionedge.com

4. Trust Index

Octagon Trust Index Kalshi 75 Good

Largest single print on SENATEIL-26-D carried 68% of its $7,200 tape (print is 8d old)

Integrity risk· Large trades

How it adds up
Integrity80% of score79Good
Trade quality20% of score57Caution

Includes the cost to trade: a $10,000 order can't be filled here because the order book is too thin.

Trust score75Good

Weighted blend with hard caps — a critically weak safety pillar, or a severe trading anomaly, caps the total regardless of the rest. Full methodology · About the Trust Index

Trust profile
Integrity4 screens run · 6 don't apply
Market integrity
70Good

Outcome is hard to influence

Large tradesTrade signals · medium confidence

Largest single print on SENATEIL-26-D carried 68% of its $7,200 tape (print is 8d old)

Thin-volume movesTrade signals · high confidence

“Juliana Stratton” made a large jump with almost no trading behind it.

Screened clean
Size patternsNo distribution read Clear
2 screens not run
Outcome control · doesn't apply to this market type
Thin-leg conviction · doesn't apply to this market type
Info fairness
80Good

Structural prior — no screens apply

No suspicious activity on any screen

Screened clean
Information exposureNo concentrated group can know the outcome materially early. Clear
4 screens not run
Move vs. catalyst · doesn't apply to this market type
Longshot repricing · doesn't apply to this market type
Pre-broadcast certainty · doesn't apply to this market type
Cross-venue timing · doesn't apply to this market type
Resolution quality
92Strong

Resolution mechanism is dependable

No suspicious activity on any screen

Resolution rules read: Clear

Liquidity
73Tradeable

Fills fine at modest size

2 contracts · worst first

Don Tracy50
Thin · low confidence

Light recent trading — size may not fill near the screen price.

Book spread 42% vs realized 4%
Juliana Stratton73
Tradeable · low confidence

Light recent trading — size may not fill near the screen price.

Move quality
66Mostly confirmed

Most moves carried real volume

2 contracts · worst first

Don Tracy66
Mostly confirmed · medium confidence

Volume opposes the move over 3d

Juliana Stratton—
No significant move (24h)

Price was stable over the last 24 hours.

Rule clarity
100Clear

Counts toward Resolution quality, not here

2 contracts · worst first

Juliana Stratton100
Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Don Tracy100
Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Trade quality
57Caution

Order book is thin

Tradable, but expect execution cost beyond small sizes.

Outcome quality 73 (notional-weighted across 2 scored legs)

$100 order: 0.5c slippage (~22% of a 2.3c contract)

$1,000 order: 3.3c slippage (~143% of a 2.3c contract)

$10,000 order: book too thin to fill

Juliana Stratton73Market scoreLiquidity73Move quality–Rule clarity100
Why 73
Liquidity
73 · Tradeable · low confidence

Light recent trading — size may not fill near the screen price.

Move quality
No significant move (24h)

Price was stable over the last 24 hours.

Rule clarity
100 · Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Don Tracy50Market scoreLiquidity50Move quality66Rule clarity100
Why 50
Liquidity
50 · Thin · low confidence

Light recent trading — size may not fill near the screen price.

Book spread 42% vs realized 4%
Move quality
66 · Mostly confirmed · medium confidence

Volume opposes the move over 3d

Rule clarity
100 · Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear

underwriting_v1.4 · computed Sep 26, 2026

5. What polling data and election forecasts support Juliana Stratton's position as the frontrunner in the 2026 Illinois Senate race?

Stratton's odds of winningApproximately 97-98% (prediction markets) [1][2]
Election forecastSolid D (for Juliana Stratton) [1][2]
Stratton's primary vote share40.4% (March 17, 2026 primary) [3][4][5][6]
Juliana Stratton is the strong frontrunner for the 2026 Illinois Senate race. She is widely considered the heavy favorite for the 2026 Illinois U.S. Senate general election against Republican nominee Don Tracy. Current election forecasts categorize the race as "Solid D," and prediction markets indicate Stratton has approximately 97-98% odds of victory [1][2]. Although specific general election polling data is not available in the bound facts, these existing forecasts and market odds strongly suggest Stratton's significant advantage [1][2]. The general election is scheduled for November 3, 2026 [5].
Stratton won a competitive Democratic primary with 40.4% of the vote. She secured her nomination in the Democratic primary on March 17, 2026, receiving 40.4% of the total vote [3][4][5][6]. Prior to her victory, the Democratic primary was a competitive contest, with pre-primary polls showing her in a neck-and-neck race against Rep. Raja Krishnamoorthi [7][8][6]. Stratton was recognized as one of three leading candidates in pre-primary polling for the 2026 Democratic primary [9].
Sources (9)
  1. 12026 Illinois Elections, Odds & Candidates | Prediction Edgepredictionedge.com
  2. 22026 Senate Races: All 35 Seats, Market by Marketpredictionmarketspicks.com
  3. 3Juliana Stratton wins Democratic Senate primary - The 19th News19thnews.org
  4. 4Stratton defeats Krishnamoorthi with help from Chicago, downstate...capitolnewsillinois.com
  5. 5United States Senate election in Illinois, 2026 - Ballotpediaballotpedia.org
  6. 62026 United States Senate election in Illinois - Wikipediaen.wikipedia.org
  7. 7Juliana Stratton Surging in Final Weeks of IL Senate Raceemilyslist.org
  8. 8Illinois election 2026: Family of Rev. Jesse Jackson clarifies...abc7chicago.com
  9. 9Ten candidates are running in the Democratic primary for U.S. Senate in Illinois on March 17, 2026 - Ballotpedia Newsnews.ballotpedia.org

6. Which major political figures and organizations have endorsed Juliana Stratton versus Don Tracy ahead of the 2026 general election?

Juliana Stratton Major EndorsementsIllinois Governor J.B. Pritzker, U.S. Senator Tammy Duckworth, Illinois House Speaker Chris Welch [1][2]
Don Tracy Major EndorsementsFormer U.S. Senator Mark Kirk, former Illinois Comptroller Leslie Munger, former State Representative Dan Caulkins [2][3]
Primary Election DateMarch 17, 2026 [2][3]
Juliana Stratton and Don Tracy secured their party nominations for the 2026 U.S. Senate election in Illinois. Both candidates successfully advanced from their respective primaries held on March 17, 2026. Stratton emerged victorious in the Democratic primary, defeating ten other candidates, while Tracy won the Republican primary against five other candidates [2][3]. They are now set to compete as the major party candidates in the general election on November 3, 2026 [2].
Juliana Stratton has received key endorsements from prominent state and federal political figures. Her notable supporters include Illinois Governor J.B. Pritzker, U.S. Senator Tammy Duckworth, and Illinois House Speaker Chris Welch [1][2]. These endorsements highlight significant backing from within the Democratic party.
Don Tracy has secured endorsements from former officials and various local Republican groups. His individual endorsers include former U.S. Senator Mark Kirk, former Illinois Comptroller Leslie Munger, and former State Representative Dan Caulkins [2][3]. Tracy also has the support of several Republican organizations, specifically the Wheeling Township and Hanover Township Republican Organizations, and the Illinois Federation of Young Republicans [2][3].
Sources (3)
  1. 1Illinois Senate race comes down to Juliana Stratton, Don Tracynbcchicago.com
  2. 2United States Senate election in Illinois, 2026 - Ballotpediaballotpedia.org
  3. 3Don Tracy - Ballotpediaballotpedia.org

7. What potential campaign missteps by Juliana Stratton or key endorsements for Don Tracy could meaningfully shift polling before the November 2026 election?

Polling Shift ImpactNo definitive shift reported from missteps or key endorsements as of September 2026 [1]
Election DateNovember 3, 2026 [2]
CandidatesJuliana Stratton (Democrat), Don Tracy (Republican) [2]
As of September 2026, no significant polling shifts are reported in the Illinois U.S. Senate race. No widely publicized campaign missteps by Democratic nominee Juliana Stratton or pivotal key endorsements for Republican nominee Don Tracy have been reported to have definitively shifted polling [1]. The available facts do not indicate any specific events that could meaningfully shift polling before the November 3, 2026, election [1].
Don Tracy has received endorsements, but they have not shifted polling. Don Tracy's endorsements include former U.S. Senator Mark Kirk, former Comptroller Leslie Munger, and various local Republican organizations and leaders [3]. However, these endorsements have not been reported as having definitively shifted polling as of September 2026 [1].
The 2026 Illinois U.S. Senate election features Stratton and Tracy. The Illinois U.S. Senate election is set for November 3, 2026, with Democratic nominee Lt. Gov. Juliana Stratton facing Republican nominee Don Tracy [2]. While prediction markets for the 2026 Illinois Senate winner are active, specific real-time winning odds are not explicitly provided by these platforms [4].
Sources (4)
  1. 1United States Senate election in Illinois, 2026 - Ballotpediaballotpedia.org
  2. 2Juliana Stratton Wins Democratic Primary to Replace Dick Durbin in...news.wttw.com
  3. 3Don Tracy - Ballotpediaballotpedia.org
  4. 4Illinois Senate winner? Odds & Predictions 2026 - Kalshikalshi.com

8. What does historical voter turnout in Illinois midterm elections suggest for the 2026 general election outcome?

Illinois Midterm Turnout (2022)45.8% (2022) [1][2]
Illinois Midterm Turnout (2018)51.5% (2018) [1][2]
Stratton 2026 Win Probability96% [3][4][5]
Illinois midterm elections consistently show lower voter turnout than presidential years. For example, turnout rates in recent midterm elections were 45.8% in 2022 and 51.5% in 2018 [1][6][2]. These figures are notably less than the 63.3% and 66.1% recorded during the 2024 and 2020 presidential election years, respectively [1][6]. Further demonstrating this trend, turnout was 40.8% in 2014, 43.1% in 2010, 41.4% in 2006, and 42.8% in 2002 [1][2].
Forecasting models strongly favor Democratic candidate Juliana Stratton in 2026. The upcoming U.S. Senate election in Illinois is an open-seat contest for the Class II seat, featuring Democratic nominee Juliana Stratton and Republican nominee Don Tracy [7][8]. Despite the historical pattern of reduced midterm turnout, political forecasting models and prediction markets heavily favor Stratton for victory. Decision Desk HQ projects a 96% win probability for Stratton, with a projected margin of D+17 [3][4][5]. The race is broadly rated as Safe/Solid Democratic, with odds for Stratton frequently exceeding 95-98% [8][9].
Sources (9)
  1. 1Voter turnout in Illinois - Ballotpediaballotpedia.org
  2. 2Election results, 2022: Analysis of voter turnout - Ballotpediaballotpedia.org
  3. 32026 Illinois US Senate Forecastvotes.decisiondeskhq.com
  4. 42026 Illinois US Senate Markets | DDHQnewsnation-votes.decisiondeskhq.com
  5. 52026 U.S. Senate Forecast | Decision Desk HQvotes.decisiondeskhq.com
  6. 6IL Voter Data: Registration by Party, Turnout & Primary Rulesindependentvoterproject.org
  7. 7United States Senate election in Illinois, 2026 - Ballotpediaballotpedia.org
  8. 82026 United States Senate election in Illinois - Wikipediaen.wikipedia.org
  9. 92026 Illinois Elections, Odds & Candidates | Prediction Edgepredictionedge.com

9. What is Don Tracy's core campaign platform and which voter demographics must he win to outperform current forecasts?

Election2026 U.S. Senate (Illinois), Republican nominee (won primary March 17, 2026) [1][2]
Core PlatformLowering costs for families (energy, gas, housing, health care) [2]
Prediction Market Standing2%-6% favorability as of September 9, 2026 (Stratton heavily favored) [3][4]
Don Tracy's campaign platform focuses on reducing family costs. As the Republican nominee for the 2026 U.S. Senate election in Illinois, having won the primary on March 17, 2026, Tracy centers his platform on addressing energy, gas, housing, and healthcare expenses [1][2]. He opposes what he describes as tax-and-spend policies and aims to represent all of Illinois, including downstate, central, and working families in Chicago [2][1]. His proposed solutions include reasonable energy policies, increased healthcare price transparency, eliminating taxpayer-funded healthcare for non-citizens, and improving government efficiency [1][2].
Current predictions favor Democrat Juliana Stratton to win the Illinois U.S. Senate seat. As of September 9, 2026, prediction markets indicate Stratton as the overwhelming favorite [3][4]. Tracy consistently polls at minimal percentages, typically between 2% and 6%, compared to Stratton's strong favorability [3][4].
Tracy must significantly broaden support to defy current forecasts. To overcome the challenge of campaigning in a Democratic-leaning state like Illinois, he would need to expand his support beyond his base [1]. This strategy involves attracting independent and swing voters, particularly in suburban areas, while simultaneously ensuring high turnout among his core supporters outside of Chicago [1].
Sources (4)
  1. 1Don Tracy - Ballotpediaballotpedia.org
  2. 2United States Senate election in Illinois, 2026 - Ballotpediaballotpedia.org
  3. 32026 Senate Races: All 35 Seats, Market by Marketpredictionmarketspicks.com
  4. 42026 Illinois Elections, Odds & Candidates | Prediction Edgepredictionedge.com

10. What Could Change the Odds

Key Catalysts

The 2026 U.S. Senate election in Illinois is scheduled for November 3, 2026, to fill the seat held by retiring Senator Dick Durbin [1]. Democrat Juliana Stratton, current Lieutenant Governor, won the Democratic primary, and Republican Don Tracy, former Illinois GOP chair, won the Republican primary on March 17, 2026 [1][2][3][4]. Other general election candidates appearing on the ballot include Independents Whitfield Harrington Jr., Tyrone Muhammad, and Anthony Smith [1][4]. As of September 9, 2026, the Cook Political Report rates the Illinois U.S. Senate race as Solid Democratic, indicating a significant electoral advantage for the Democratic nominee [5].
While the Illinois Senate race is rated Solid Democratic, national control of the U.S. Senate in 2026 is considered a toss-up by prediction markets [5][6]. Market prices for national Senate control frequently fluctuate between a slight Republican edge and near-even odds [6]. Key catalysts for these national market probabilities include the correlated nature of competitive state races, national generic ballot polling, candidate recruitment, and the impact of the current administration's approval ratings [6][7][8]. The winners of the general election on November 3, 2026, are scheduled to take office on January 3, 2027 [9][10].

Key Dates & Catalysts

  • Expiration: November 03, 2027
  • Closes: November 03, 2027
Sources (10)
  1. 1United States Senate election in Illinois, 2026 - Ballotpediaballotpedia.org
  2. 2Illinois Lt. Gov. Juliana Stratton wins Democratic primary for US Senate | AP Newsapnews.com
  3. 3United States Senate election in Illinois, 2026 (March 17 Democratic...ballotpedia.org
  4. 4Don Tracy - Ballotpediaballotpedia.org
  5. 5Illinois Senate Race 2026 — Juliana Stratton (D) vs. Don Tracy (R) | Solid Democratic | USPollingData.comuspollingdata.com
  6. 6Polymarket's 52-cent Senate coin flip is a structural mispricing. The generic ballot says 57. | Noah Intelligencenoah-news.com
  7. 7Senate 2026 Odds: Live Prediction Market Tracker for Chamber Control – Bellwetherbellwether.market
  8. 82026 US Senate Control Odds & Analysis | Prediction Geniuspredictiongenius.io
  9. 92026 election and voting dates - Ballotpediaballotpedia.org
  10. 10United States Senate elections, 2026 - Ballotpediaballotpedia.org