An off-year election is one which takes place in a year when a presidential election does not also take place.
Most elections in the United States take place in even-numbered years. As the US Senate’s website notes:
National Elections take place every even-numbered year. Every four years the president, vice president, one-third of the Senate, and the entire House are up for election (on-year elections). On even-numbered years when there isn’t a presidential election, one-third of the Senate and the whole House are included in the election (off-year elections).
Typically, voter turnout is far greater in years when there’s also a presidential election; off years generate much less interest among the public. The organization FairVote has found that in recent years, around 60 percent of eligible voters make it to the polls in years when there’s a presidential election; in contrast, 40 percent of voters cast a ballot during midterm elections. Those figures are lower for odd-year and local elections. (It’s worth adding that in the 2020 presidential election, at least 64 percent of eligible voters turned out to cast a ballot, the highest percentage of voting to take place since at least 1908.)
In general, voter turn-out in the United States lags behind turnout in other highly developed democracies. The Pew Research Center has examined voting data from the 35 members of the Organization for Economic Cooperation and Development, a grouping of wealthy democracies. When Pew ranked the level of voter turnout from those 35 countries, the United States came in 30th in the list. That’s just looking at voter turnout during presidential election years; the numbers are far lower during midterm elections, as we have seen.
Some writers have lambasted off-year elections as the “steamed peas” of elections – they’re unglamorous and slightly boring, even if there’s nothing really wrong with them. The conventional wisdom is that off-year elections are won by conservative groups and, perhaps, by Republicans, simply because those groups probably have better-disciplined support bases who can be counted on to turn out the vote, even in an off-year.
However, some political analysts argue that off-year elections really skew towards any interest group that can mobilize voters around a single cause. Sarah Anzia, an assistant professor of political science at Berkeley, argued that off-year elections give a lot of power to unions and other pressure groups. She told an interviewer:
When elections are held in off years or on unusual days, the people who do show up are the ones who really care about the outcomes, and usually this means that well-organized groups are overrepresented. Oftentimes, in local government, it means that government employees and their unions have outsized influence. It makes sense that they would be really politically engaged, because what these local governments do affects their jobs very directly. So especially when elections are off-cycle, firefighters have disproportionate influence in the elections of fire protection districts and cities, and teachers unions have disproportionate influence in school board elections.