Wave elections (1918-2016)/U.S. House waves since 1918

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June 19, 2018
By: Rob Oldham and Jacob Smith

The metaphor of a wave implies that once a party wins a large number of seats, those gains will eventually recede, much like a tide being pulled back into the ocean.

An instructive example of this is the Democrats' performance in U.S. House elections from 2006 to 2016. Following the 2004 elections, Democrats had 201 seats, which was 17 below the 218 seats required for a majority. However, over the next two elections Democrats brought themselves to 233 seats and then to 256 seats. Neither election constituted a wave on its own, but, together, the gains were large enough to qualify 2006-2008 as a combined wave.

As the metaphor implies, though, Democratic gains soon began to recede. In 2010, Republicans erased the 2006-2008 combined wave with a wave of their own. From 2012 to 2016, Democrats remained in the minority as they won some seats back in 2012, lost them again in the 2014 Republican resurgence, and then began to gain ground again in 2016. Democrats are now hoping that 2018 is a wave that they can ride to shore and eliminate Republican advances since 2010.

The graph below gives a visual representation of Democratic performance since 2004.

A similar story of waves and receding tides can be told for Republicans from 1944 to 1994. Republicans captured the House in the 1946 wave, the first time they controlled the chamber since the 1930 Democratic wave. However, they only briefly held power as Democrats took the chamber back in 1948. After that, Republicans more or less entered a receding tide period for the next 46 years although they briefly took the House back in 1952 (before losing it again in 1954) and had a wave in their favor in 1966 (which did not lead to them recapturing the chamber). It was not until 1994 that Republicans caught a wave that was finally large enough to dislodge the Democratic majority.

The graph below gives a visual representation of Republican performance from 1944 to 1994.

Before 1944, waves happened at a more rapid pace than we saw during the mid- to late-century Democratic dominance of the House. In fact, six of the 11 wave elections happened from 1920 to 1942, with three going against each party. Often precipitated by national emergencies, these elections led to massive swings in seats.

The first wave occurred in 1920 when House Republicans bolstered the majority they first won in 1916. The GOP gains were so great that their House majority narrowly survived a Democratic wave in 1922. It was another eight years before the onset of the Great Depression led to two back-to-back waves against Republicans in 1930 and 1932 and a Democratic takeover of the House. In the years following 1932, Democrats built their majority up enough that they survived Republican waves in 1938 and 1942.

The full record of waves and tides from 1918 to 2016 can be seen in the graph below.

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