Prices as of August 25, 2026, at 3:13 p.m. Eastern. Record compiled from 20 dated sources; see the sourced record file for every citation.
On Sunday, August 23, the Boston Globe's editorial board told the Eighth Congressional District to retire a 25-year incumbent. Its endorsement of Patrick Roath ended on one line: "The people of the Eighth District deserve more than backbench representation." It landed four days after the same paper reported that a super PAC founded by David Hogg had put more than $250,000 behind Roath, and three days after that PAC published a poll showing the race inside single digits.
Then the people with money on the outcome went the other way. On Kalshi, where a price in cents is the crowd's probability, a contract that pays $1 if Rep. Stephen Lynch wins the September 1 primary closed at 52¢ on August 22 and 55¢ the night of the endorsement. By Tuesday afternoon it sat at 56¢ bid, 58¢ ask: buyers offering 56, sellers asking 58. On Polymarket, Roath had been the favorite from August 12 through August 21. He is now 44¢, and Lynch is up 8.5¢ there on the week.
A 57¢ Lynch is roughly what a sportsbook would post as -133: risk $133 to win $100. Roath at 43¢ is the +133 side. That is a favorite with a thumb on the scale, not a lock, and the book behind it is small: about $23,600 in open positions on the Lynch contract, with 33 contracts waiting to buy and 21 waiting to sell. A few hundred dollars moves this number; on Tuesday it printed as high as 85¢ and as low as 50¢, and neither print meant anything.
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The Board
As of August 25, 2026, 3:13 p.m. ET (Kalshi, cents = probability):
| Outcome | Price | Reads as |
|---|---|---|
| Stephen Lynch | 56¢ bid / 58¢ ask (57¢ mid; last trade 55¢) | about 57% (≈-133 in sportsbook terms) |
| Patrick Roath | 42¢ bid / 44¢ ask (43¢ mid; last trade 42¢) | about 43% (≈+133) |
The crowd sees Lynch as a 57% shot, a coin flip with a lean. Polymarket agrees within two cents: Lynch 55¢ (54¢ bid, 56¢ ask), Roath 44¢ (43¢ bid, 45¢ ask), with Lynch up 8.5¢ and Roath down 11¢ over seven days. On a book this thin, read the bid and the ask, not the last trade.
What the Models Think
We also asked a panel of AI models the same question. Six of the panel's eight seats ran this board, without seeing the price, with only the sourced record below. Their middle answer, the blended median, put Lynch at 78.5%, well above the 57¢ market; the widest gap between two models was 12 points, 68% to 80%. A real gap in the incumbent's favor, for consistent reasons: House incumbents rarely lose primaries without a scandal, Lynch leads even in polls his challenger's allies paid for, and he carries three times the cash. One model put it this way: "Even the pro-Roath PAC's own poll has Lynch ahead 50-43 with a cash lead entering the final week."
The split is easy to name: the models weigh incumbency and discount the challenger-paid polls; the bettors weigh the momentum and an incumbent stuck at 50 in anyone's survey. The market has real money behind it; the panel has only the record. These are model estimates, not predictions.
How It Got Here
Lynch, 71, grew up in the South Boston housing projects, ran Iron Workers Local 7 at 30 and has held the seat since 2001, per the Patriot Ledger's August 25 profile. Roath, 39, is a voting-rights attorney from Jamaica Plain and a former Deval Patrick aide, per WGBH on August 3, with about a decade at the law firm Ropes & Gray.
The challenge rests on two roll calls the House Clerk keeps. On January 22, 2025, Lynch voted Yea on the Laken Riley Act while the other eight Massachusetts Democrats voted Nay. On March 21, 2010, he was the only Massachusetts member voting No on the Affordable Care Act, one of 34 Democrats who did. The record also holds what the attack omits: on January 9, 2025, when 45 Democrats crossed over on the Illegitimate Court Counteraction Act, Lynch did not.
The money runs opposite to the polls. Roath out-raised Lynch over the cycle, about $1.28 million to $910,000, but on the August 12 pre-primary filings Lynch held roughly $642,000 in cash to Roath's $220,000. Lynch has the labor slate, led by the Massachusetts AFL-CIO; Roath has Patrick, the teachers' unions and now the Globe. It is the same shape as the New Hampshire primary where the money spent a day catching up to a poll, a cousin of the Florida primary the market called before the votes did, and every other 2026 race with a live price sits on one board.
The Fight
Every poll in this race was paid for by Roath's side. The Globe's Kelly Garrity wrote on August 17 that "there's been no independent public polling of the race so far."
| Field dates | Pollster / who paid | Lynch | Roath |
|---|---|---|---|
| Feb 17–19 | Workbench Strategy / Roath campaign | 62 | 36 |
| Jul 12 | Z to A Research / Leaders We Deserve (pro-Roath PAC) | 54 | 32 |
| Aug 5–6 | Z to A Research / Leaders We Deserve, 469 likely voters, ±4.5 | 50 | 43 |
That August number is the "single digits" the PAC is mailing about. Its own words, in its August 20 Substack post, are "conservative Democrat Stephen Lynch" and the "ONLY Massachusetts Democrat to vote with Republicans for the Laken Riley Act."
Then the mail. The Globe reported on August 19 that Roath's website said he "is the only candidate in this race refusing corporate donations," and that "almost word-for-word, the blurb appeared on a multipage mailer that Leaders We Deserve … sent out on his behalf earlier this month." Campaigns cannot legally coordinate with super PACs; posting the message you want mailed where the PAC can read it is called red-boxing. Lynch's campaign counted a sixth mailer that day and put the PAC's spending at $357,651.15; we could not reconcile that with the Globe's figure.
The two men shared a stage once, August 13 in Weymouth, and South Shore News and Boston.com both filed the next day. Roath accused Lynch of taking "millions of dollars in corporate PAC money" and called the Laken Riley vote "disqualifying." Lynch: "The PACs that I have accepted money from are the iron workers … nine cents an hour, $3.60 a week." On the mailers: "they're all from PACs that he's working with, so that's phony baloney." On Ropes & Gray: "One, they bust unions for a living. Number two, they push for-profit health care." Lynch tied private-equity hospital ownership to Steward's bankruptcy; Roath answered, "I just had nothing to do with Steward, never worked on it, no idea anything about it." On Trump, Lynch said, "When Trump says immigrants are poisoning the blood of our nation, your Nazi alarm should go off."
"The people of the Eighth District deserve more than backbench representation." The Globe's editorial board, August 23. The Lynch contract closed at 55¢ that night, up from 47¢ on August 20, the day the PAC's post went up.
Open interest, the dollars actually committed, grew from about $4,000 on August 12 to about $23,600 on Tuesday. The Clerk's Laken Riley roll call has not changed in that time; what changed is who was willing to pay for a position.
What Moves The Price From Here
Thursday, August 27, 7 p.m., Dedham Middle School. A second forum. Roath has confirmed; Westwood Minute corrected its own report that Lynch would attend. A solo stage and the empty chair beside it both push toward Roath.
An independent poll, if one appears. None exists. A neutral survey inside five points pushes toward Roath; a neutral Lynch lead near 10 likely ends the argument.
Who actually votes. Early voting runs August 22–28; the mail-ballot application window closed Tuesday at 5 p.m. Suffolk's David Paleologos told the Patriot Ledger: "Older people, union members will vote. Women." The primary falls before many colleges are back in session. Both lean Lynch.
This one settles on Tuesday, September 1, 2026, polls open 7 a.m. to 8 p.m. The winner faces Republican Robert Gerald Burke in a district every rating outfit calls safe for Democrats, so the primary is the election.
Hero illustration: OddsShopper, in the house collage style. Massachusetts State House photo by Gunnar Klack, licensed CC BY-SA 4.0; photos cropped, toned, and composited. Prices quoted are live Kalshi market prices as of August 25, 2026, at 3:13 p.m. Eastern, and will keep moving until this market settles after the Tuesday, September 1, 2026 vote. Kalshi is a CFTC-regulated event-contract exchange (18+; availability varies by state). OddsShopper covers prediction markets as an independent analyst: any model or panel figures referenced are model estimates, not predictions of fact and not financial advice. This article does not advocate for or against any candidate or party. Trading involves risk; contracts can go to zero.
