This market resolves YES if a special election for a US House seat is completed in 2027 and the winner is a Republican, where the seat's vacating member was a Democrat (see definitions).

When an election counts as "in 2027":

- The election that actually fills the seat must take place between January 1 and December 31, 2027 (inclusive).

- This can be a special general election, a runoff, or a special primary or all-party first round in which one candidate wins outright by majority and so fills the seat.

- A special election whose primary or first round is in 2027 but which needs a general election or runoff in 2028 does not count.

- The vacancy may have arisen at any time, including before 2027. Only the date the seat is filled matters.

Who counts as the seat's "vacating member":

- Sitting member: the person who created the vacancy (by resigning, dying, being expelled, etc.) while in office and who, at that moment, caucused with the Democratic Party in the House. This includes Democrats and independents who caucus with Democrats.

- Member-elect: if the 2026 winner never took office (died, resigned or was not seated before swearing in), they count as a Democrat if they won the 2026 general election as the Democratic Party's nominee.

- A member who switched parties before the vacancy is judged by the party they caucused with at the time of the vacancy, or for a member-elect, the party on the ballot.

Excluded:

- A special election held because the 2026 (or any earlier) election was annulled, voided or ordered rerun, as with the 2019 North Carolina 9th. In that case there is no incumbent or member-elect, so it does not count.

- Delegates from DC and US territories.

Republican winner: the winner's party as listed in the state's certified results or by the AP. Independents who caucus with Republicans do not count unless listed as Republican.

Seat identity: a seat is identified by its state and district number. Redistricting and the district's partisan lean do not matter.

Resolution:

- Resolves YES once the AP calls a qualifying race, or official results show a qualifying Republican win, and no recount is pending.

- If a recount or certified correction changes the result, the certified result controls.

- One qualifying race is enough if several occur.

- Court rulings or House actions after the election (e.g., refusing to seat the winner) do not change the resolution.

- Resolves NO at 11:59 PM ET on December 31, 2027 if no qualifying race has occurred.

Sources: certified results from the relevant state election authority; AP race calls; Ballotpedia's list of special elections.