Kalshi
PolymarketTX-28 Is Priced on the Incumbent's Vote, Not on a Map That Now Leans the Other Way at the Top of the Ticket
TX-28 House race odds are priced on an incumbent's own vote in a district the redraw moved toward the Republicans. The seat as drawn for 2026 runs from Laredo and Webb County down the Rio Grande through Zapata and Starr counties into 36% of Hidalgo County, and north through Duval, Jim Hogg and La Salle counties to Atascosa and Live Oak, and it is 90.8% Hispanic on the 2020 Census. Texas voters decide it on November 3, 2026, and the market treats the sitting member's record as the whole race: the Democratic contract has been the favourite on both venues since primary day, March 3, 2026, even though the Republican presidential ticket carried the new district by ten points in 2024. The live board above has the current number. The price rests on a person here more than on any other Texas House board this site follows, and that is both the read and the risk.
What the TX-28 price is saying
Start with what changed, because in TX-28 the redraw is the story. Under the previous plan, PlanC2193, the district held 13% of Bexar County, 251,965 people, and 60% of Guadalupe County, 103,849 people, alongside Webb, Starr, Zapata, Atascosa, Duval, Jim Hogg and McMullen counties, and it was 75.3% Hispanic and 17.2% Anglo. PlanC2333, the plan the 89th Legislature enacted in its second called session of 2025 for the 2026 elections, drops Bexar and Guadalupe entirely and adds 36% of Hidalgo County, 317,042 people, all of Dimmit, La Salle and Live Oak counties and 21% of Maverick County. The district that results is 90.8% Hispanic and 7.4% Anglo, and its Spanish-surname share of registered voters is 80.2% against 61.9% under the old lines, on the Texas Legislative Council's tables for the November 5, 2024 general election. That is the largest demographic shift of any seat this site follows in Texas, and the price has to be read against it.
The 2024 returns inside the new lines are what make this a contest rather than a hold. The Republican presidential ticket carried the new TX-28 by 54.8% to 44.4% on November 5, 2024, up from 53.1% to 45.8% under the old lines, but the Senate race split almost exactly even, 48.8% Republican to 48.6% Democratic, and the down-ballot races landed in between: 51.6% to 48.4% for the Republican in one Supreme Court race, 46.0% to 44.2% in the Railroad Commission race with a Green candidate at 7.7%. Registration inside the new lines was 421,469 with a 47.5% turnout, the lowest of the three Texas seats on this site, down from 476,277 and 52.9% under the old map. A district that votes ten points Republican for president and even for senator is a district where the name on the House line decides the House race, which is exactly what the price is saying.
The name is the sitting member's. Henry Cuellar of Laredo, a Democratic member sworn in on January 3, 2025 according to the Clerk of the House's member list for the 119th Congress, filed for the March 3, 2026 Democratic primary on December 3, 2025, listing his occupation as U.S. congressman, alongside two other Democratic filers, Andrew Vantine of Mission and Ricardo Villarreal of Laredo. The Secretary of State's certified general-election list carries three names: Cuellar for the Democratic Party; Tano E. Tijerina for the Republican Party, who filed on December 4, 2025, listed his occupation as county judge and was one of two Republican filers for the primary alongside Eileen Day of Georgetown; and Marlón Durán for the Green Party, a community organizer who filed on December 6, 2025. In the November 5, 2024 general election under the old lines Cuellar took 125,280 votes, 52.79%, to 112,018, 47.21%, for the Republican candidate, Jay Furman. A five-and-a-half point win in a district the Democratic presidential ticket lost by seven points is the personal vote the market is pricing.
The money on this board sits on Kalshi, and it has for a year. Kalshi's TX-28 series opened on July 1, 2025, six months before the exchange listed the other Texas House seats, and on September 23, 2026 it carried $182.1K of the $192.3K matched across both venues, $144.4K on the Democratic contract and $37.7K on the Republican one; Polymarket's event, opened on December 15, 2025, carried $10.2K. Kalshi's Democratic contract was 88% and Polymarket's 86% on September 23, 2026, with the Republican contracts at 14% on both, which means the deep book and the thin one agree that the incumbent's margin travels onto the new map, and the two-point gap between them is the price of the thin book's volatility rather than a second opinion. That is the most money and the widest gap between books of the three Texas House pages here, because the Kalshi book has a year of positions behind it and the Polymarket book is thin enough to move on a single order.
Polymarket's Democratic contract opened on December 17, 2025 at 50%, was 46.5% on January 1, 2026, printed a low of 41.5% on February 9, 2026, and was 69% on primary day, March 3, 2026. It has closed above 60% on the first trading day of every month since: 73% on April 2, 67% on May 1, 76.5% on June 1, 81.5% on July 1 and on August 1, 82% on September 1 and 85.5% on September 23, 2026. The Republican contract printed as high as 57.5% on June 5, 2026 on that thin book, a number the Democratic side never confirmed, and it was 13.5% on September 23, which means a trader who bought the Republican side in June has watched three quarters of that price disappear without a vote being cast. A market that opened at even money and climbed to the mid-eighties before any ballot was counted is a market that decided the incumbent's 2024 margin travels with him onto the new map.
The case against the TX-28 read
The case against the read is arithmetic. Inside the 2026 lines the Republican presidential ticket won by ten points on November 5, 2024, and the Senate race was a tie; the House race Cuellar won that year was fought on lines that included 251,965 people in Bexar County and 103,849 in Guadalupe County who are no longer in the district, and did not include the 317,042 people in Hidalgo County who are. His 52.79% has never been tested on this map. A reader who holds the other view says the 2024 margin belongs to the old district, that the new one voted more Republican at the top of the ticket than the old one did, and that an 87% price is paying for a personal vote whose size on these precincts is unknown.
Turnout cuts the same way. The new district's 47.5% turnout on November 5, 2024 was the lowest of the three Texas seats on this site and a presidential-year number; the council's table has the same lines at 34.6% in the 2022 general election. A midterm in a district of 421,469 registered voters, 80.2% of them with Spanish surnames, is decided by which side turns out a thin electorate, and nothing in the record says which side that favours on these lines. The Green Party's place on the ballot, in a district where the Green candidate for Railroad Commissioner took 7.7% within the new lines on November 5, 2024, is a third variable the two-party price does not carry.
And the market has already priced this seat as close. The Republican contract's 57.5% print on June 5, 2026 on Polymarket, three months after the primary, says that even on a thin book traders were willing to pay better than even money for the other side in June. The record does not say why, and this page does not guess; it says that a contract which was a coin flip in June and 14% in September moved on something other than a vote, and that what moved it once can move it again.
What changes the TX-28 read
The read is wrong if the personal vote does not travel. The numbers to watch are the Republican contract on Kalshi, where the money is, and the early vote in Hidalgo and Webb counties.
• The Republican contract on Kalshi above 25%: it was 14% on September 23, 2026; a move above 25% on the deep book after early voting opens on October 19, 2026 would say the market has stopped trusting the 2024 margin on the new map, and this read would be dead.
• The Hidalgo County early vote, October 19 to October 30, 2026: 317,042 of the district's 766,987 people are new to it and live in Hidalgo County; the share of the early vote coming from Hidalgo against Webb is the first read on whose electorate this is.
• The next federal fundraising reports: the Federal Election Commission's next quarterly totals are the first look at whether either campaign has the money to contest a 421,469-voter district that now runs from Laredo into Hidalgo County.
• A fixed ballot: August 21, 2026 was the last day to withdraw from or be declared ineligible for the general election, so the three names are set; voter registration closes on October 5, 2026.
When the TX-28 market resolves
Texas holds the general election on Tuesday, November 3, 2026, with early voting from October 19 through October 30 and voter registration closing on October 5, 2026. Polymarket's contracts resolve on the party of the candidate who wins the seat, by ballot-listed affiliation at the time all 2026 House elections are conclusively called by a consensus of credible reporting, with the Federal Election Commission's official results as the tiebreaker if reporting is ambiguous; the event's listed end is November 5, 2026 at 04:59 UTC. Kalshi's HOUSETX28-26 contracts, open since July 1, 2025, pay Yes if the House member sworn in for TX-28 for the term beginning in 2027 belongs to the named party, allow accelerated determination once a consensus of media organizations projects the winner, expect settlement on January 4, 2027, carry a listed expiration of November 3, 2027 and close following the swearing-in. Members elected under the previous plan continue to represent the old districts until the next Congress convenes in January 2027. Each venue also lists a contract on another party winning the seat, which is the contract that would pay if the Green Party candidate won; Polymarket's carried no volume on September 23, 2026.
Related TX-28 markets
The two other House seats this site follows on the same map are the Texas 21st District market, an open Republican seat west of Austin and San Antonio where the sitting member is not on the ballot, and the Texas 24th District market, a held Republican seat in Tarrant and Dallas counties the redraw left almost untouched. Both resolve on the same November 3, 2026 vote and on the same party rule. The Texas politics hub carries the full set of state boards, the elections page lists every race with a contract, and the markets catalogue has the rest of the Texas inventory.
