2018 election analysis: Control of the U.S. House
Updated September 9, 2020
This content is part of Ballotpedia's analysis of the 2018 midterm elections. For comprehensive election results, click here.
Heading into the November 6, 2018, midterm election, Republicans held a 235-193 advantage over the Democratic Party in the 435-member U.S. House of Representatives. All 435 seats—including seven vacancies—were up for election, with Democrats needing to add 23 seats to win majority control of the chamber.
The Democratic Party was well-positioned to gain seats, according to a 100-year historical analysis of House elections conducted by Ballotpedia and political scientist Jacob Smith. From 1918 to 2016, the president’s party lost an average of 29 seats in midterm elections. The Democrats matched this pattern in the 2018 midterms, gaining 40 seats for a total of 235 seats—17 more than was needed for a majority.
One undecided 2018 race was decided in September 2019 when Dan Bishop (R) won the special election. The state board of elections called a new election following allegations of absentee ballot fraud in the 2018 race. Click here for more information on the aftermath of the 2018 election.
In 372 of the 435 seats, an incumbent was seeking re-election on November 6. There were 52 seats where the incumbent was either retiring or otherwise not seeking re-election—18 Democrats and 34 Republicans, including House Speaker Paul Ryan (R-Wisconsin)—and seven vacant seats. In four other seats, the incumbent—two from each party—was defeated in a primary before election day.
There were 46 seats that changed party hands, both open seats and those occupied by an incumbent, and 30 of the 372 incumbent U.S. representatives (8.1 percent) lost their seats in the general election—all Republicans.
Thirty-eight seats up in 2018 were won by the presidential candidate of the opposite party in 2016: Hillary Clinton (D) won 25 Republican-held districts, and Donald Trump (R) won 13 Democratic-held districts. On November 6, 2018, Democrats won 22 of the 25 Clinton-leaning seats held by Republicans after 2016, while Republicans won two of the 13 Trump-leaning seats held by Democrats.
Partisan balance
- See also: United States House of Representatives
| U.S. House Partisan Breakdown | |||
|---|---|---|---|
| Party | As of November 5, 2018 | After the 2018 Election | |
| Democratic Party | 193 | 235 | |
| Republican Party | 235 | 200[1] | |
| Vacancies | 7 | 0 | |
| Total | 435 | 435 | |
See also
- 2018 election analysis: State government trifectas
- 2018 election analysis: Partisan balance of state legislative chambers
- 2018 election analysis: Incumbents defeated in state legislative elections
- 2018 election analysis: State legislative supermajorities
- 2018 election analysis: Partisan balance of governors
- 2018 election analysis: State government triplexes
- 2018 election analysis: Control of the U.S. Senate
- 2018 election analysis: Was 2018 a wave election?
Footnotes
- ↑ One undecided 2018 race was decided in September 2019 when Dan Bishop (R) won the special election. The state board of elections called a new election following allegations of absentee ballot fraud in the 2018 race. Unofficial returns from the 2018 election showed Mark Harris (R) leading McCready, who was also the Democratic candidate in 2018, by 905 votes. Harris said he did not run again in 2019 due to health issues. Click here for more information on the aftermath of the 2018 election.
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