Vacancies in Congress

Seats in Congress become vacant when a member dies, resigns, is expelled, or is appointed to another office, and in a typical Congress there are several vacancies in each chamber. The Constitution treats the chambers differently. House vacancies can be filled only by special election called by the state's governor, so a district may go months without a voting representative. Under the Seventeenth Amendment, states may allow governors to appoint a temporary senator until a special election, and most states do, while a few require the appointee to be from the same party as the former senator.

While a House seat is vacant, the Clerk of the House supervises the former member's office staff so constituents can still get help with federal agencies, but no one can vote on their behalf. Vacancies change the size of the House, so the number of votes needed for a majority falls as seats become empty. To guard against a catastrophe that kills or incapacitates many members, a 2005 law requires expedited special elections when more than 100 House seats are vacant, and the House adopted rules allowing a provisional quorum if many members cannot attend.

Vacancies can shift power when margins are narrow. In 2025, resignations of members who joined the administration and the deaths of several members left the House majority with very little room to lose votes, and the swearing-in of one member elected in a September special election was delayed for weeks while the House was out of session, drawing criticism from the other party. Supporters of the current system say only voters should choose House members, while some continuity experts propose a constitutional amendment allowing temporary appointments to the House in a national emergency.