Ohio Senate Special 2026

Ohio holds a Senate special election on November 3, 2026 to fill the seat JD Vance vacated. Jon Husted, appointed to it in January 2025, is defending against Sherrod Brown, who held the state's other seat for eighteen years before losing it in 2024. Kalshi's Ohio Senate winner? book turned $52,448 today.

In September the reason to watch it was that the exchanges disagreed about who was ahead: Kalshi had Husted at 51.5%, Polymarket had Brown at 51.5%. That has resolved. Brown leads on all three venues: 62.5% on Kalshi, 61.5% on Polymarket and 62.4% on Manifold. The two exchanges have not moved in three days; Manifold has come up three points to meet them. The spread between the two exchanges is one point.

Kalshi carries the depth, Polymarket the second-largest book, and Manifold the independent third read. All three have Brown ahead by more than twenty points, and all three settle on the same election, so the one-point gap between Kalshi and Polymarket is venue disagreement rather than a difference in contract language.

The two candidate legs priced directly. Of Kalshi's $52,448 in 24-hour turnover, $36,767 sits on the Brown leg against $15,681 on Husted's: seven dollars in ten on the leader, a little less than three days ago. Polymarket leans the same way and harder, with $8,578 of its $8,670 on Brown at 61.5%.

Two ways of asking how close this gets. The margin Cumulative prices a Republican win by 2+ points at 28.5% and by 6+ at 7.5%. The Governor-Senate combo has an Acton/Brown Democratic sweep at 57%, up from 53.5%, and a Ramaswamy/Husted Republican sweep at 26%, with the split tickets at 13.5% and 7.5%. See also Ohio Governor 2026.

How this race sits against the rest of the cycle. The closest-race book ranked Ohio third in September; it is fifth at 8.45%, behind Iowa at 18%, Texas at 12.5%, and Maine and Kansas at 10.5%. The four-state tossup combo prices a Democratic sweep of Texas/Alaska/Iowa/Ohio at 33.5%, up from 29.5%, against a Republican sweep at 12.5%.

• The sign flip closed in Brown's favor. Kalshi 62.5%, Polymarket 61.5%, Manifold 62.4%. In mid-September Kalshi had Husted ahead. The one-point gap that remains is the spread to watch.
• The flow is on the leader. $36,767 of Kalshi's $52,448 and $8,578 of Polymarket's $8,670 traded on Brown.
• The margin ladder. Husted by 2+ at 28.5% and by 6+ at 7.5%: a Republican win, if it comes, is priced as narrow.
• Split-ticket risk. The combo book puts 21% on a split between the Governor and Senate races, and prices Acton-and-Husted, at 13.5%, as the likelier of the two.
• Certification lag. Kalshi settles on the certified result in early January 2027, Polymarket on the November 3 outcome. If the race is close, the two could sit apart for weeks after the votes are counted.
• This is a special election. The winner serves the remainder of the term, and the seat is up again in 2028.