Kalshi listed its 2028 House contracts in May 2026, more than two years before anyone votes, and the traders on that board are already pricing against the steadiest pattern in modern American politics. Since 1946 the House of Representatives has changed hands in a presidential election year exactly twice, in 1948 and in 1952. Eighteen straight presidential elections have passed without one, a run of 72 years. Traders on this board are paying about 30 cents on the dollar for Republican control after 2028, and most of the path to that outcome runs straight through the thing that has not happened since Harry Truman was president.
We asked eight AI models the same question with the price hidden from all of them, handed each one the full postwar control ledger, the live polling aggregates and the enacted-map record, and let them read each other's reasoning and revise. They landed on the market's number almost to the decimal. That agreement is the story, because both sides of it are pricing against the history book.
This is a neutral, data-driven look at market prices, the public record and historical patterns. It does not advocate for any party, candidate or outcome.
The Quick Answer
Kalshi prices Democratic House control after 2028 at 68.5 cents and Republican control at 29.5 cents, as of August 22, 2026. Our eight-model, price-blind panel lands at 69.4% for Democratic control after a revision round, which is the middle of the eight numbers, not their average, with every model between 64% and 76%. Traders and models agree on the number and on the reason: the 2026 midterm is the first of two gates, and whoever wins it starts 2028 as a favorite that the modern era has made less safe than the record implies. The full board, the two steps every seat priced, and the four things that would move this number are below.
Every seat priced this market the same way, in two steps: who wins the November 3, 2026 midterm, and whether that winner still holds the gavel after November 7, 2028. The raw historical answer to those two questions and the number both traders and models actually printed are five points apart, and that gap is the subject of everything below.
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The Market At A Glance
| Venue | Kalshi, a CFTC-regulated event-contract exchange (18+; availability varies by state, as of August 2026) |
| The Event | "2028 House winner" (Kalshi CONTROLH-2028), two mutually exclusive party contracts |
| The Contract | Per the settlement rules, verbatim: "If the Democratic party has won control of the House in 2028, then the market resolves to Yes" (mirror wording for the Republican contract) |
| How It Settles | Verbatim: "This market may be determined early based on a consensus of media calls projecting control of the U.S. House. See full rules for details. Otherwise, victory will be determined by the party identification of the Speaker of the House on February 1, 2029." |
| Key Dates | Election day November 7, 2028; the new House organizes in January 2029; expected expiration February 1, 2029 (15:00 UTC) |
| Depth | About 9,600 contracts of lifetime volume across both sides, roughly 4,700 of them still open. Both sides show a five-cent gap between the best price to buy and the best price to sell. This is a thin book, and that caveat runs through everything below |
| Prices Below As Of | August 22, 2026, 09:35 UTC (the midpoint between the best live buy and sell quotes on each contract) |
These are model estimates, not predictions of fact and not financial advice. Kalshi event contracts trade on a CFTC-regulated exchange; you must be 18 or older and in an eligible state to participate. Every number in this piece gets graded in public once the market settles, on our full graded scoreboard.
The Fight That Already Drew The 2028 Map
The districts these races will be run in were redrawn during a mid-decade war that reached the Supreme Court twice inside five months. One side of that war is settled for 2028. The other is still in court, and which one is which turns out to matter more for this board than anything in the polls.
Texas moved first. The legislature passed HB 4, a mid-decade congressional map, on August 23, 2025, and Governor Greg Abbott signed it on August 29. The map was drawn to shift the state's delegation from 25 Republicans and 13 Democrats toward 30 and 8. On November 18, 2025 a three-judge federal panel in the Western District of Texas blocked it, finding that the redistricting "constituted a racial gerrymander". The Supreme Court stayed that injunction 6-3 on December 4, 2025 and summarily reversed it on April 27, 2026, holding that the district court had "failed to honor the presumption of legislative good faith" and had "improperly inserted itself into an active primary campaign." The map governs 2026. The lawsuit itself, LULAC v. Abbott, is still pending on the merits: civil-rights plaintiffs allege the map violates Section 2 of the Voting Rights Act, and no court has ruled on that allegation. The Texas lines for 2028 are the single largest open question on this board.
California answered the redistricting fight at the ballot box, and the backlash was not close. On November 4, 2025 voters approved Proposition 50 by 64.42% to 35.58%, a margin of 28.84 points, under a title that named its own purpose: "Authorizes Temporary Changes to Congressional District Maps in Response to Texas' Partisan Redistricting." That measure hands map-drawing to the legislature for the 2026, 2028 and 2030 elections, after which the state's independent commission resumes in 2031. Federal courts declined to block it and the Supreme Court refused to pause it before the midterms.
Ten states enacted new congressional maps ahead of 2026, eight of them redrawn to Republican advantage and two to Democratic advantage; NBC News' tally puts Republicans in position to gain up to 16 seats from the redraws against up to six for Democrats. Measured against 2028 instead of 2026, that record cuts in an odd direction. California's advantage is locked in by its own ballot language. Texas's is the one under active legal threat. Two seats on our panel revised in the second round on exactly that asymmetry, and one of those kept its headline number while moving the pieces underneath it.
What The Record Actually Says About Presidential Years
The panel's data card carried no prices and no punditry. Its spine was the full party-division ledger for every House election from 1946 to 2024, parsed at run time rather than recalled, and the base rates that fall out of it are unusually clean.
- Control Turnover Is A Midterm Event. The House changed hands in seven of the last 20 midterms: 1946, 1954, 1994, 2006, 2010, 2018 and 2022. It changed hands in two of the last 20 presidential years, and both were more than seven decades ago.
- The Carry-Over Rate Is The One That Governs This Market. A party that flipped the House in a midterm went on to hold it at the next presidential election six times out of seven. The lone failure was 1946 into 1948: the Republican majority elected in that midterm was swept out two years later on Truman's upset, with Democrats gaining 74 seats.
- The Exceptions Needed Swings Nobody Produces Now. 1948 moved 74 seats in a night. 1952 moved 22, on a presidential margin of 10.85 points and 442 electoral votes. Net change in Democratic House seats at each presidential election since 1956 has been mostly single digits, with the two largest at plus 37 in 1964 and minus 35 in 1980. Reagan's 1980 landslide moved 35 seats and still did not flip the chamber.
- Winning The White House Does Not Deliver The House. In eight of the 20 presidential years since 1948 the two went to different parties, most recently in 2012.
- The Midterm-Penalty Rate Does Not Apply Here. The famous statistic, that the president's party lost House seats in 18 of 20 postwar midterms, is a fact about midterms. 2028 is a presidential year. Any model that imports it into this market has made a category error, and the card said so explicitly.
Put the pieces together and the naive answer is straightforward. One public forecast, the fiftyplusone model published August 3, 2026, gives Democrats an 85% chance of winning the 2026 House with a median projection of 230 seats in a range of 211 to 253. Multiply that 85% by the six-of-seven carry-over rate, 85.7%, and you get 72.8%. Add the branch where Republicans hold 2026 and then lose the chamber back in 2028. The ledger's rate for any presidential-year flip is 2 in 20, or 10%, so 15% of the time times 10% adds another 1.5 points. Total, about 74% for Democratic control after 2028. The market is at 68.5. The panel is at 69.4. Both are shaving about five points off the history book, and both give the same reason for it.
The Board: Market Vs. The Eight Models
| Outcome | Market (mid) | AI blend | Gap |
|---|---|---|---|
| Democratic House Control After 2028 | 68.5¢ | 69.4% | +0.9 |
| Republican House Control After 2028 | 29.5¢ | 30.6% | +1.1 |
These are model estimates, not predictions of fact and not financial advice. The blend is the seat median of eight models' final numbers after a revision round in which each read the others' anonymized reasoning. The two market midpoints sum to 98 because the two contracts trade in separate order books, each with its own buy and sell price.
Every Seat's Number
| Seat | P(Democratic control), round 1 | Final (after revision) | Conditional hold priced in round 1 |
|---|---|---|---|
| Claude Fable | 62.5 | 64.0 | 74% |
| Claude Opus | 72.7 | 74.0 | 82% |
| Claude Sonnet | 68.5 | 68.0 | 80% |
| ChatGPT | 66.7 | 69.0 | 77% |
| Gemini Pro | 68.6 | 69.0 | 79% |
| GLM | 69.6 | 72.0 | 82% |
| Kimi | 77.0 | 76.0 | 85% |
| DeepSeek | 53.8 | 69.8 | 80% |
Every seat on this panel is graded against real market settlements — records to date: Claude Fable 82% on 576 graded calls · Claude Opus 83% on 646 graded calls · Claude Sonnet 82% on 624 graded calls · GPT 84% on 5,658 graded calls · Gemini 86% on 4,423 graded calls · GLM 81% on 2,437 graded calls · Kimi 82% on 2,414 graded calls · DeepSeek 80% on 2,462 graded calls. Recomputed daily; the full scoreboard is public.
More live boards from the same panel: House control 2026, where the same two-contract question settles first, has Democratic control at 84.5¢ · 2026 Senate control has Republican control at 53.5¢ on the same election night · 2028 presidential election has the Democratic party contract at 57.5¢. Prices fetched August 22, 2026.
The last column is the one worth staring at. Seven of the eight priced the chance that the 2026 winner still holds the House in 2028 BELOW the six-of-seven historical rate of about 86%, landing between 74% and 82%. The eighth, Kimi, came closest at 85%. The panel is that close to unanimous on a single question: the postwar carry-over rate was earned in an era of large majorities, and it does not survive contact with a chamber that currently sits at 219 Republicans, 212 Democrats and four vacancies.
Where The Panel Changed Its Mind
Round two moved the board 16 points at the bottom and barely touched the top. The biggest revision came from the seat that had been alone in the low 50s, and it moved because it caught its own error. It had set aside extra probability for a messy, undecided outcome, then decided that hedge was not earned.
"I held my step-1 (83% D) and Democratic conditional-hold (80%) estimates but corrected a combination error that had overweighted divided-outcome tail risk. Peer arguments consistently applied the base rate without a large tail, and I adjusted Republican conditional hold from 85% to 80% to reflect narrow-majority vulnerability, aligning with the symmetric discount applied to Democrats." — DeepSeek
Two seats moved for the same reason, and it is a genuinely subtle one about how polling error is measured. The card's graded-poll archive shows presidential-year polls overstating Democrats by 3.7 points in 2016 and 4.7 in 2020, while the two midterms without Trump on the ballot were nearly unbiased at minus 0.3 in 2018 and plus 0.9 in 2022. Round one, two seats had applied the presidential-year haircut to the whole estimate.
"Moved 73 to 74 on one specific correction. In round 1 I let the Trump-era presidential-year poll bias (+3.7 in 2016, +4.7 in 2020) shade my estimate down as a general 'presidential years overstate Democrats' caution. Forecaster A's separation of the steps forced me to look at the archive again: the bias splits cleanly by whether Trump was on the ballot (+3.7 and +4.7 with him; -0.3 in 2018 and +0…" — Claude Opus
A third seat caught itself double-counting the maps, which is the easiest mistake to make on this subject: the public 2026 forecast it was leaning on had already been built on the enacted maps, so its own extra deduction for redistricting was charging the same toll twice.
"I was double-counting redistricting headwinds in Step 1: the fiftyplusone model published August 3, 2026 was already built on the enacted maps (Texas HB4 signed August 2025, Supreme Court reversal April 2026, all other redraws in place), so my 5-point haircut from 85% to 80% discounted for maps the model already absorbed." — GLM
And one seat sat at the panel's center and refused to move, which in a convergence round is its own kind of evidence.
"Held. The eight peers span 54-77% with a mean of 67.5 — my 68% already sits at the center, so this isn't a case of an isolated outlier needing correction. I checked each peer for evidence I hadn't priced: Forecaster C's move to 54% rests on an unexplained ad hoc 'tail for a divided outcome,' not new evidence — I don't adopt unjustified hedges." — Claude Sonnet
The Two Steps Every Seat Priced
Asked as a single question, this market invites a hunch. Broken into two, it becomes a pair of numbers anyone can check.
Step one, the 2026 midterm. All eight seats put Democrats between 82% and 85% to win the House on November 3, 2026, clustering just under the public model's 85%. The live inputs point the same way: a six-aggregator generic-ballot average of Democrats 47.8% to Republicans 41.5% as of August 20, 2026, and presidential approval averaging 37.6% approve to 59.3% disapprove across ten aggregators as of August 17. The card also told every model to test the two midterms that broke the pattern, 1998 and 2002, against present conditions, not as generic caution. One needed an impeachment backlash, the other a rally-around-the-flag with presidential approval above 60. Neither condition appears in the fetched numbers, and the seats that reported the test said so.
Step two, the hold. This is where the panel earns its keep, and where it parts company with the raw record. Seven of the eight priced that hold between 74% and 82% in round one, against a historical 86%, and six of those seven named the same mechanism: majority size. Claude Sonnet was the exception, pointing instead at the map tilt, since the redraws net Republicans more seats than Democrats and Texas's HB 4 still governs while its case is pending. A 253-seat majority is close to unflippable in a presidential year. A bare 218-seat majority is one retirement and two bad districts from gone. The public model's range runs from 211 seats, which is not a majority at all, up to 253, so the panel is pricing across shapes that behave nothing alike. Kimi was the lone seat to sit at the base rate, at 85%, arguing the map litigation gives Democrats a live upside chance that offsets the fragility of a thin majority. Round two barely moved the column: GLM raised its Democratic hold to 83%, Kimi held at 85%, DeepSeek held at 80%, and ChatGPT recorded that its 77% had been "too punitive relative to the 6-of-7 carry-over base rate."
The eight final answers, sorted, run 64, 68, 69, 69, 69.8, 72, 74 and 76. The middle of that list is 69.4%, and every one of them was built from the same two components: a step-one estimate around 82% and a conditional hold around 80%. The market sits at 68.5 cents. Two methods that never saw each other's work arrived within a point, and neither of them treats the streak as being as safe as 18 straight elections make it look.
The Case Each Side Is Priced On
Both cases get the same structure and the same amount of room.
The case carried by the 69% side. Two gates both favor the same party right now. The 2026 environment is about as one-sided as a midterm environment gets, with approval more than 21 points under water and a generic ballot above six. History then says the winner keeps it: 18 straight presidential elections without a flip, and six of seven midterm flippers holding. The five seats Texas drew for itself are the ones still being defended in court, while California's counter-map is written into state law through 2030.
The case carried by the 30% side. The 2026 election has not happened, ten weeks is long enough for an environment to move, and the environment of November 2028 is unknowable today. A Democratic win can also arrive at the bare minimum, and a 218-seat majority is a rounding error away from gone. The redraws still net Republicans more seats than Democrats. Presidential-year polling in the Trump era overstated Democrats by three to five points, and 2028 will be an open race under the 22nd Amendment with two nominees nobody can name today. And the contract does not settle on election night: it settles on the party of the Speaker on February 1, 2029, which in a chamber decided by a handful of seats is not a formality.
What Would Change The Panel's Mind
Every seat named its own falsifiers. These four double as this page's re-score triggers.
- The November 3, 2026 Seat Count. This is the single biggest input and it resolves in ten weeks. A Democratic majority at or above 230 seats pushes the conditional hold back toward the historical 86% and this number toward the mid-70s. A majority of 218 to 220 pushes it the other way, hard. One seat said explicitly that 225 or fewer Democratic seats would move it toward a coin flip.
- A Merits Ruling In LULAC V. Abbott. The Texas map is the largest structural variable that is still legally live. A ruling that strikes the 2025 lines before 2028 removes seats from the Republican column that the current price assumes; a ruling that upholds them removes an upside tail the panel is currently crediting to Democrats.
- The Generic Ballot And Approval Through The Fall. Both feed step one directly. A sustained move of two to three points in the generic ballot, or an approval recovery toward even, weakens the leg that carries most of the 69%. The exception conditions run in both directions: a rally-scale national event before November 2026 would re-open the 1998 and 2002 precedents and cut the base rate that anchors this whole page.
- The 2028 Nominees. Coattails, meaning a presidential result big enough to carry House candidates from the same party in with it, are the one mechanism that has ever flipped a House in a presidential year, and the two cases did not look alike. 1952 paired a 22-seat House swing with Eisenhower's 10.85-point win. 1948 paired a 74-seat swing with Truman's upset, which was only a 4.48-point margin. Once the two fields take shape, a race pointing at either shape is the specific thing that would justify a Republican number well above 30.
Settlement Timeline
| Next Catalyst | November 3, 2026: the midterm that decides which party defends the House in 2028 |
| Then | Merits proceedings in LULAC v. Abbott, which determine the Texas map for 2028 |
| Then | The 2028 primary calendar and both parties' nominees, from spring into summer 2028 |
| Election Day | November 7, 2028 |
| Settlement | Early determination on a consensus of media calls, otherwise the party of the Speaker on February 1, 2029 (expected expiration 15:00 UTC that day) |
| Re-Score Policy | This page is re-scored on the same URL when the story moves, and every number on it is graded in public after settlement. Prices above are as of August 22, 2026 |
How To Read A Thin Two-Contract Market
Two things about this particular board are worth teaching before anyone treats its price as gospel.
The first is depth. The 2026 House contracts on the same exchange have traded about 23.8 million contracts in their life. The 2028 contracts have traded about 9,600. Both boards ask a nearly identical question about the same chamber, and one of them carries roughly 2,500 times the volume of the other. A price with that little behind it is a real quote from a small number of participants, and it should be read that way.
The second is the spread, which is the gap between what buyers are bidding and what sellers are asking. On the Democratic contract that gap is five cents wide, 66 bid against 71 asked. Anyone who buys at the ask and sells at the bid gives up those five cents before the election happens at all, and on a position held for 29 months that friction is part of the real cost. On the 2026 board the same spread is one cent. The 68.5-cent midpoint is the center of a band rather than a decimal-precise reading of the crowd. A price in the high 60s implies that traders, on balance, are pricing a Republican House after 2028 at a bit less than one time in three from here, and that implied figure moves with whatever bid and ask are actually showing at the time.
The mechanics of the venue itself, and where these contracts sit legally, are covered in our guide to prediction market legality. The same panel's work on the race that decides this board's first gate lives on the 2026 midterm board, and the day's full slate of graded calls sits on our daily Kalshi hub.
The panel's calls are on the record. Our 8-model AI panel puts a graded, public verdict on the 2026 House race that decides who defends this chamber in 2028, and you can read the live model verdict for that board, scored the same way this one was.
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The Bottom Line
Traders and models agree on the 2028 House, at 68.5 cents against a 69.4% median, and the agreement is more interesting than a disagreement would have been. Both are pricing about five points below what the postwar record alone would produce. Six of the eight models gave the same reason for that discount, that modern House majorities are too thin for a base rate built in the era of 250-seat chambers; one pointed at the redrawn maps instead, and one stayed on the historical rate. The number that resolves the argument arrives on November 3, 2026. If Democrats clear 230 seats, this board should drift toward the mid-70s. If they scrape in at 218, the streak that has held for 72 years gets its most serious test since Eisenhower. Either way this page gets re-scored on the same URL, and the panel's call gets graded in public.
These are model estimates, not predictions of fact and not financial advice. Kalshi event contracts trade on a CFTC-regulated exchange; participation requires being 18+ and in an eligible state.
Hero illustration: OddsShopper, in the house collage style. United States Capitol west front photo by Beethoven, licensed CC BY-SA 4.0; photos cropped, toned, and composited.
