Wave elections (1918-2016)/Election types
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House waves • Senate waves • Gubernatorial waves • State legislative waves |
Competitiveness in State Legislatures |
June 19, 2018
By: Rob Oldham and Jacob Smith
Wave elections occur disproportionately in first and second midterm elections.
First midterm elections account for 30 percent of elections since 1918, but they comprise more than 30 percent of wave elections for the U.S. House (54.6 percent), gubernatorial races (72.7 percent), state legislatures (40.0 percent), and composite scores (40.0 percent).
Second midterm elections account for 18 percent of elections since 1918, but they comprise more than 18 percent of wave elections for the U.S. Senate (30.0 percent), state legislatures (30.0 percent), and composite scores (20.0 percent).
Presidential elections account for 50 percent of elections since 1918, but they comprise less than 50 percent of wave elections for the U.S. House (18.2 percent), U.S. Senate (30.0 percent), gubernatorial races (18.2 percent), state legislatures (30.0 percent), and composite scores (30.0 percent).
The chart below compares each election type's representation among the 10 or 11 wave elections to the election type's representation among all 50 elections (which is listed in the top row). Percentages for Election type, House waves, and Senate waves do not add to 100 percent because Franklin Roosevelt had a third midterm election in 1942 where House and Senate waves occurred.
| Election type analysis | ||||||
|---|---|---|---|---|---|---|
| Election type | First midterms (30%) | Second midterms (18%) | Presidential elections (50%) | |||
| House waves | 54.6% | 18.2% | 18.2% | |||
| Senate waves | 30.0% | 30.0% | 30.0% | |||
| Gubernatorial waves | 72.7% | 9.1% | 18.2% | |||
| State legislative waves | 40.0% | 30.0% | 30.0% | |||
| Composite waves | 40.0% | 20.0% | 30.0% | |||
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Footnotes