Short Answer

Both the model and the market expect Democrats to win Michigan's 8th District by 2 or more points, with no compelling evidence of mispricing.

1. Market Behavior & Drivers

This market's price chart is defined by a single, decisive movement. It began at a very low probability of 1.0% before experiencing a massive surge to 88.0%. This dramatic spike directly reflects the market reacting to the conclusive election results. The provided context indicates that the Democratic candidate, Kristen McDonald Rivet, won the election by a 6.7 percentage point margin. Once this outcome was reported, traders rapidly repriced the contract to reflect the near-certainty that the final margin would fall within the range required for a "YES" resolution. The price has since stabilized in the high 80s, currently trading at 89.0%.
The market shows a total volume of 1,186 contracts traded, suggesting a reasonable level of participant activity. The massive price jump from near zero to the high 80s has established a strong support level in that range, as the market is unlikely to price in any other outcome now that the election is over. The current price of 89.0% indicates extremely high market confidence in a "YES" resolution. The sentiment is not speculative; rather, it reflects the known, factual outcome of the election. Traders are expressing a very strong consensus that the reported 6.7% margin of victory satisfies the market's resolution criteria.
  • The district has an R+1 Cook Partisan Voting Index.
  • Midterm elections may pose headwinds for the president's party.
  • Incumbent's early fundraising appears to fall below benchmarks.
  • The Democratic incumbent won in 2024 with a 6.7 percentage-point margin.
  • Presidential approval ratings historically influence midterm election outcomes.
  • A Republican primary will select a challenger in August 2026.

Who Wins and Why

Outcome Market Model Why
Democrats, 2+ pts 89.0% 81.1% The incumbent faces an R+1 district and fundraising challenges, suggesting a narrower victory.
Democrats, 11+ pts 0.0% 5.0% The incumbent faces an R+1 district and fundraising challenges, suggesting a narrower victory.
Democrats, 14+ pts 0.0% 2.0% The incumbent faces an R+1 district and fundraising challenges, suggesting a narrower victory.
Democrats, 17+ pts 0.0% 1.0% The incumbent faces an R+1 district and fundraising challenges, suggesting a narrower victory.
Democrats, 20+ pts 0.0% 0.5% The incumbent faces an R+1 district and fundraising challenges, suggesting a narrower victory.

Current Context

Democrats secured a notable victory in Michigan's 8th District in 2024. Kristen McDonald Rivet won the election with 51.3% of the vote, defeating Paul Junge, who received 44.6% [1][2][3]. This resulted in a margin of victory of 6.7 percentage points, representing a difference of 28,173 votes (217,490 for Rivet vs. 189,317 for Junge) [1][2][3]. Looking ahead to the 2026 election, major political handicappers currently rate Michigan's 8th Congressional District as "Lean Democratic." This consensus view is reflected by ratings from Cook Political Report, Inside Elections, and Sabato’s Crystal Ball, as tracked by Ballotpedia [4].
The 2026 election schedule is set, with varying prediction market odds. Key dates for the Michigan 8th District election include the filing deadline on April 21, 2026, followed by the Republican primary on August 4, 2026, and the general election on November 3, 2026 [4][5]. Current implied probabilities from prediction markets show a range of expectations for the upcoming contest. One listing indicates an 84% probability for Democrats to win, with Republicans at 14% [6]. A separate, mirrored listing presents different odds, placing Democrats at 64% and Republicans at 39% [7]. This highlights the dynamic nature of these market-derived probabilities.
Sources (7)
  1. 1Michigan House District 8 Election 2024 Live Resultsnbcnews.com
  2. 2Michigan's 8th Congressional District election, 2024 - Ballotpediaballotpedia.org
  3. 32024 MI General Election Results - U.S. House District 8heraldtimesonline.com
  4. 4Michigan's 8th Congressional District election, 2026 - Ballotpediaballotpedia.org
  5. 5Michigan's 8th Congressional District election, 2026 (August 4 Republican primary) - Ballotpediaballotpedia.org
  6. 6MI-08 House Election Winner Predictions & Odds | Polymarketpolymarket.com
  7. 7MI-08 House Election Winner Predictions & Odds | Polymarketworldcoin.polymarket.com

2. Price Chart

Historical Price (Probability)

Outcome probability
Date

3. Market Data

Contract Snapshot

This market resolves to Yes if the Democratic Party wins the 2026 U.S. House election in Michigan's 8th District by 11 percentage points or more; otherwise, it resolves to No. The market opened on May 5, 2026, and closes early upon publication of certified election results from the official election authority (otherwise by November 3, 2027), with payouts projected 30 minutes after closing. The margin of victory is calculated as the Democratic Party's vote percentage minus the runner-up's, with no rounding applied.

Available Contracts

Market options and current pricing

Outcome bucket Yes (price) No (price) Last trade probability
Democrats, 2+ pts $0.90 $0.11 89%
Democrats, 11+ pts $0.52 $0.49 0%
Democrats, 14+ pts $0.42 $0.59 0%
Democrats, 17+ pts $0.32 $0.69 0%
Democrats, 20+ pts $0.21 $0.80 0%
Democrats, 23+ pts $0.14 $0.87 0%
Democrats, 5+ pts $0.74 $0.27 0%
Democrats, 8+ pts $0.67 $0.34 0%

Market Discussion

Kristen McDonald Rivet won Michigan's 8th Congressional District election by 6.6 percentage points [1][2][3], with another analysis indicating a 6.7-point victory [4]. This election was for an open seat after the incumbent retired [1][2], and The Cook Political Report had rated the race as a "toss-up" [5]. The district has experienced varied margins in recent elections, including a 10.3-point Democratic win in 2022 [1][6], and narrower Democratic victories of 3.6 points in 2020 [1][4] and 4 points in 2018 [5].

Sources (6)
  1. 1wdet.org
  2. 2washingtonpost.com
  3. 3michiganindependent.com
  4. 4welcomestack.org
  5. 5wcmu.org
  6. 6ballotpedia.org

4. Trust Index

Octagon Trust Index Kalshi 79 Good

Order book is critically thin.

Primary risk· Trade quality

How it adds up
Integrity80% of score90Strong
Trade quality20% of score37High Risk

Includes the cost to trade: a $1,000 order can't be filled here because the order book is too thin.

Trust score79Good

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
83Good

Outcome is hard to influence

No suspicious activity on any screen

Screened clean
Large tradesTape too thin Clear
Thin-volume movesPrice moves carried real volume. Clear
Size patternsTape too thin 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
95Strong

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
46Thin

Expect slippage beyond small size

5 contracts · worst first · 3 below the volume floor — not scored

Rivet, 20+ pts40
Thin · low confidence

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

Rivet, 11+ pts46
Thin · low confidence

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

Rivet, 23+ pts53
Thin · low confidence

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

Rivet, 2+ pts—
No recent trading to measure

No recent trading to measure

Rivet, 8+ pts—
No recent trading to measure

No recent trading to measure

Move quality
68Mostly confirmed

Most moves carried real volume

5 contracts · worst first · 3 below the volume floor — not scored

Rivet, 23+ pts62
Mostly confirmed · high confidence

Volume opposes the move over 6h

Rivet, 20+ pts76
Confirmed · medium confidence

Volume confirms the move over 3d

Rivet, 2+ pts—
No trading in 3d

No trades in the last 3d — nothing to confirm

Rivet, 8+ pts—
No trading in 2d

No trades in the last 2d — nothing to confirm

Rivet, 11+ pts—
No trading in 3d

No trades in the last 3d — nothing to confirm

Rule clarity
100Clear

Counts toward Resolution quality, not here

5 contracts · worst first · 3 below the volume floor — not scored

Rivet, 2+ pts100
Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Rivet, 8+ pts100
Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Rivet, 11+ pts100
Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Rivet, 20+ pts100
Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Rivet, 23+ pts100
Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Trade quality
37High Risk

Order book is critically thin

Thin market — entering or exiting at fair value will be difficult.

Outcome quality 46 (notional-weighted across 3 scored legs)

$100 order: 3.0c slippage (~3% of a 95.1c contract)

$1,000 order: book too thin to fill

$10,000 order: book too thin to fill

3 below the volume floor — not scored

Rivet, 2+ pts–Market scoreLiquidity–Move quality–Rule clarity100
Why this score
Liquidity
No recent trading to measure

No recent trading to measure

Move quality
No trading in 3d

No trades in the last 3d — nothing to confirm

Rule clarity
100 · Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Rivet, 8+ pts–Market scoreLiquidity–Move quality–Rule clarity100
Why this score
Liquidity
No recent trading to measure

No recent trading to measure

Move quality
No trading in 2d

No trades in the last 2d — nothing to confirm

Rule clarity
100 · Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Rivet, 11+ pts46Market scoreLiquidity46Move quality–Rule clarity100
Why 46
Liquidity
46 · Thin · low confidence

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

Move quality
No trading in 3d

No trades in the last 3d — nothing to confirm

Rule clarity
100 · Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Rivet, 20+ pts40Market scoreLiquidity40Move quality76Rule clarity100
Why 40
Liquidity
40 · Thin · low confidence

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

Move quality
76 · Confirmed · medium confidence

Volume confirms the move over 3d

Rule clarity
100 · Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear
Rivet, 23+ pts53Market scoreLiquidity53Move quality62Rule clarity100
Why 53
Liquidity
53 · Thin · low confidence

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

Move quality
62 · Mostly confirmed · high confidence

Volume opposes the move over 6h

Rule clarity
100 · Clear · high confidence

All checks pass

objective outcome · Clearofficial source · Cleartime boundary · Clear

underwriting_v1.4 · computed Sep 23, 2026

5. What do the 2020 and 2024 presidential election results within Michigan's 8th District reveal about its baseline partisan lean heading into the 2026 midterms?

Cook PVIR+1 [1][2][3]
2024 Presidential WinnerDonald Trump [1]
2024 House WinnerKristen McDonald Rivet (D) with 51.2% [4]
Michigan's 8th District shows a Republican lean post-redistricting. Designated R+1 by the 2023 Cook Partisan Voting Index, this indicates it performs one percentage point more Republican than the national average in presidential elections [1][2][3]. While Joe Biden lost the district by approximately one percentage point in the 2020 presidential election under its former boundaries [5], a significant redistricting in 2023 reshaped the district around Flint and the Tri-Cities metropolitan area [1]. Under these new geographical lines, Donald Trump won Michigan's 8th District in the 2024 presidential election [1].
The 2024 election showcased notable split-ticket voting behavior. Adding nuance to its partisan lean, the 2024 presidential election saw Michigan's 8th District emerge as one of just 13 congressional districts nationwide that elected Trump for president while simultaneously electing a Democratic House representative [1]. Democrat Kristen McDonald Rivet secured the House seat with 51.2% of the vote, defeating her Republican challenger Paul Junge, who garnered 44.6% [4].
Sources (5)
  1. 1wikipedia.orgen.wikipedia.org
  2. 2wikipedia.orgen.wikipedia.org
  3. 3ballotpedia.org
  4. 4npr.orgapps.npr.org
  5. 5datausa.io

6. Which potential Republican challengers could emerge from the August 2026 primary, and how might their ideological profiles affect the general election against Kristen McDonald Rivet?

Republican Primary DateAugust 4, 2026 [1][2]
General Election DateNovember 3, 2026 [1][2]
Incumbent Rivet's Last Vote Share51.3% [3]
The Republican primary will select challenger for Michigan's 8th District. The August 4, 2026 Republican primary for Michigan's 8th Congressional District will feature candidates Amir Hassan, Al Lemmo, and Thomas J. Smith [1]. The primary winner will advance to challenge the incumbent Democrat, Kristen McDonald Rivet, in the general election scheduled for November 3, 2026 [2]. The district is characterized as "ripe" for Republicans, suggesting the ideological leanings of the GOP nominee could significantly impact the general election outcome [3]. Rivet's last general-election vote share was 51.3%, indicating a potentially narrow margin in the upcoming contest [3].
Candidates Hassan and Lemmo present distinct ideological platforms. Amir Hassan's campaign is defined by an "America First Republican" platform, aligning with the agenda of former President Trump [4][5]. His stated positions include opposition to "radical open-border" policies and the "Green New Deal," along with advocating for the cessation of "woke DEI" initiatives, the deportation of illegal immigrants, and the exclusion of LGBTQ issues from school curricula [4][5]. Al Lemmo's campaign emphasizes a strong pro-life stance, articulating that "children...begins in the womb" [6][7]. He also supports law enforcement, opposes defunding efforts, and advocates for a "smaller government" approach [6][7]. Details on the ideological profile of Thomas J. Smith are not available in the provided information. The specific ideological emphasis adopted by the Republican nominee is expected to significantly influence the general election against Rivet [3].
Sources (7)
  1. 1Michigan's 8th Congressional District election, 2026 (August 4 Republican primary) - Ballotpediaballotpedia.org
  2. 2Michigan's 8th Congressional District election, 2026 - Ballotpediaballotpedia.org
  3. 3Michigan MI-08 House: 2026 | Cook Political Reportcookpolitical.com
  4. 4Amir Hassan for Congresshassanformi.com
  5. 5Amir Hassan mounts 2026 challenge in Michigan’s 8thourmidland.com
  6. 6Lemmo for Congresslemmoforcongress.com
  7. 7Alfred Lemmo - Ballotpediaballotpedia.org

7. How does Rep. Kristen McDonald Rivet's fundraising in the 2026 cycle compare to her 2024 performance and benchmarks set by other incumbents in 'Lean Democratic' districts?

Q1'26 Quarterly Fundraising$894,610 [1]
Q1'26 Cash-on-Hand$2.63M [1]
2024 Total Fundraising$6,067,032 [2][3]
Representative Kristen McDonald Rivet has demonstrated early fundraising momentum for her 2026 cycle. Her Q1’26 quarterly committee fundraising reached $894,610, with 68.24% originating from individual contributions, and she reported $2.63 million in cash-on-hand [1]. These figures contrast with her performance in the 2024 cycle, where her total fundraising amounted to $6,067,032 [2][3]. In the 2024 general election for Michigan's 8th Congressional District, she secured victory with 51.3% of the vote, defeating her Republican opponent by a margin of approximately 6.7 points [4].
McDonald Rivet's cash-on-hand demonstrates a competitive financial position. While her Q1’26 quarterly committee fundraising of $894,610 [1] falls below the approximately $2 million benchmark for a "serious" candidate [5], her reported cash-on-hand of $2.63 million [1] places her competitively. This cash-on-hand figure is within the $2–5 million range commonly observed for incumbents in "top 15 toss-up districts" during Q1 [5], indicating a strong financial position for the upcoming cycle.
Sources (5)
  1. 1Fundraising in Michigan's 8th Congressional District | Quiver Quantitativequiverquant.com
  2. 2Kristen McDonald Rivet – 2024 Fundraising, Spending & Donors | LegiListlegilist.com
  3. 3MCDONALD RIVET, KRISTEN - Campaign Finance | Who Funds Congresswhofundscongress.com
  4. 4McDonald Rivet wins Michigan's 8th Congressional District racefreep.com
  5. 5Q1 2026 Fundraising: Top Senate and House Candidates, ActBlue vs. WinRed | USPollingData | USPollingData.comuspollingdata.com

8. What is the expected schedule for public polling releases for MI-08, and what was the historical accuracy of these pollsters in the 2024 election cycle?

MI-08 Polling Release ScheduleNot specified in available research [1]
Change Research Avg Error (district polls)5.52% [2]
Public Policy Polling AccuracyWithin one point of final margin in 19 of 42 districts [3]
No specific public polling release schedule exists for Michigan's 8th District. The available research does not specify an expected schedule for public polling releases specifically for Michigan's 8th District (MI-08). While some election forecasting models, such as those by The Hill and Decision Desk HQ (DDHQ), did incorporate polling data for MI-08 as part of their daily updates on the race, some prominent pollsters, like AtlasIntel, did not publish any district-level polls [1][2].
Change Research showed improving accuracy closer to election day. Regarding pollster accuracy in the 2024 election cycle, Change Research conducted over 370 general or primary election polls, including for U.S. House candidates [4]. Their district polls, encompassing congressional district polls, had an average error of 5.52% [2]. This accuracy improved to an average error of 3.0 points for 53 polls conducted in the final 30 days before the election [4]. The research does not specify if Change Research conducted or publicly released polls specifically for MI-08.
Public Policy Polling demonstrated strong accuracy across many districts. Separately, Public Policy Polling (PPP)'s polls were within one point of the final margin in 19 of 42 districts, within three points in 30 districts, and within five points in 39 districts in 2024 [3]. Similar to Change Research, the provided information does not specify if PPP conducted or publicly released polls specifically for MI-08. For context, in the November 5, 2024, general election for MI-08, Democrat Kristen McDonald Rivet secured 51.25% of the votes to Republican Paul Junge's 44.61% [5][6].
Sources (6)
  1. 1thehill.comelections2024.thehill.com
  2. 2activote.net
  3. 3publicpolicypolling.com
  4. 4changeresearch.com
  5. 5ballotpedia.org
  6. 6michiganindependent.com

9. Historically, how have midterm election outcomes in districts with a similar profile to MI-08 been influenced by the sitting president's approval rating?

Highest-correlation variable for House seat lossesPresidential approval rating [1][2]
Average House losses for president's party (approval below 50%)Around 27 losses [2]
Average House losses for president's party (approval below 45%)About 37 losses [2]
Historically, presidential approval ratings significantly influence midterm congressional election outcomes [1][2]. Peer-reviewed studies consistently identify presidential popularity as the single highest-correlation variable for House seat losses for the president's party, with this impact often stronger when the president’s party is a notable incumbent factor [1].
Specific presidential approval thresholds predict the number of House seats lost [2]. When presidential approval is above approximately 60%, the president's party typically experiences minimal House losses [2]. Conversely, approval below 50% generally leads to an average of about 27 House losses, a figure that increases to around 37 losses if approval falls below 45% [2]. These trends underscore a strong correlation between the president's standing and their party's midterm performance [3].
However, MI-08's profile presents a nuanced case against general trends [4][5][2]. While general trends are clear, specific historical data for districts with a precise profile like MI-08's R+1 Cook PVI is not available in the provided facts [4][5][2]. Michigan's 8th District is characterized as being about 1 percentage point more Republican than the national average in presidential voting [4][5]. Despite this slight Republican lean, the district has recently elected Democratic representatives in House elections, including in 2020 and 2024 [6]. This suggests that local candidate or distinct district-level dynamics can occasionally supersede broader national midterm trends driven by the presidential party [6].
Sources (6)
  1. 1Economic Conditions, Presidential Popularity, and Voting Behavior in Midterm Congressional Electionsjournals.uchicago.edu
  2. 2Midterm History: Seat Losses by President's Party Since 1930 — Average -28 House, -4 Senate | USPollingData.comuspollingdata.com
  3. 3https://arxiv.org/pdf/1503.07545arxiv.org
  4. 4The Cook Partisan Voting Index (Cook PVI℠) | Cook Political Reportcookpolitical.com
  5. 5Michigan's 8th Congressional District - Ballotpediaballotpedia.org
  6. 6https://en.wikipedia.org/wiki/Michigan's_8th_congressional_districten.wikipedia.org

10. What Could Change the Odds

Key Catalysts

Kristen McDonald Rivet (D) won Michigan’s 8th District with 51.3% against Paul Junge (R) at 44.6%, a 6.7 percentage-point margin of victory in 2024 [1][2]. Prediction-market pricing for the “MI-08 House Election Winner” on Polymarket indicated the “Democratic Party” at ~84% and the “Republican Party” at ~14%, reflecting a strong Democratic tilt in market-implied probabilities [3].
Key dates for the MI-08 2026 election calendar include the filing deadline on Apr 21, 2026, the primary election on Aug 4, 2026, and the general election on Nov 3, 2026 [4][5].

Key Dates & Catalysts

  • Expiration: November 03, 2027
  • Closes: November 03, 2027
Sources (5)
  1. 1Michigan Eighth Congressional District Election Results 2024nytimes.com
  2. 2Michigan's 8th congressional districten.wikipedia.org
  3. 3MI-08 House Election Winner Predictions & Odds | Polymarketpolymarket.com
  4. 4Michigan's 8th Congressional District election, 2026 - Ballotpediaballotpedia.org
  5. 5Michigan MI-08 House: 2026 | Cook Political Reportcookpolitical.com