As of December 9, the results of two U.S. House elections remain uncertain. The election in New York’s 22nd Congressional District is too close to call amid an ongoing legal challenge surrounding partial recounts. In Iowa’s 2nd Congressional District, Mariannette Miller-Meeks (R) was certified as the winner by state election officials as winning by a margin of six votes. Runner-up Rita Hart (D) announced she would contest the results before the U.S. House’s Administration Committee. Both elections are on track to be among the closest Congressional races in recent decades.
In 2018, 1,894 elections within Ballotpedia’s coverage scope were decided by margins of 10 percentage points or fewer, including primaries where candidates won election outright.
Broken down by level of office, 105 of these races were federal, 1,217 were state-level, and 572 were local.
Federal races in 2018 were decided by a smaller average margin-of-victory (MOV) than in any even-year elections since 2012. The narrowest MOV in 2018 was 0.12 percentage points in Florida’s U.S. Senate election.
At the state level, the narrowest MOV was 0.008 percentage points in the election for Kentucky House of Representatives District 13. Among local races within our coverage scope, the narrowest margin was 0.017 percentage points in the election for one of Maricopa County’s seats on the Central Arizona Water Conservation board.
There were 258 races decided by margins under one percentage point in 2018. This includes 20 races where the MOV was ten votes or fewer. Two races in 2018 were decided by a single vote: the election for District 1 of the Alaska House of Representatives and the election for District 13 of the Kentucky House of Representatives.