primary runoff elections

By Wendy Underhill and Katharina Owens Hubler  | Vol . 25, No. 32 / August 2017


Did you know?

  • The use of primary runoffs is most common in the South, where there is a history of one-party rule.
  • One way that states are using ranked-choice voting, or instant runoff voting, is for military and overseas voters.
  • Cost, turnout and timing are the three biggest drawbacks to using primary runoffs.

Plurality voting—also known as “winner-take-all, or “first-past-the-post” in England—is the most common form of voting in the United States. In this system, voters select one candidate per race and the candidate with the most votes wins. If the candidate field is large, the winner can be elected by less than 50 percent of the vote (and certainly with no mandate).

In a race between three candidates, for example, one could receive 20 percent of the vote, another 35 percent of the vote, and the winner 45 percent of the vote. In this scenario, the candidate with 45 percent of the vote wins—even though a majority of voters preferred someone else.

With a two-party system, the issue of a candidate receiving less than 50 percent of the vote is not common in general elections. It is also not unheard of: In Maine, the governor has been elected with less than 50 percent of the votes in nine of the last 11 elections. In five of them, the governor won with less than 40 percent. Where plurality voting really matters is in primary contests, where it is common to have a handful of candidates.

Ten states require a candidate to win a primary with a majority of the votes. If no candidate gets to that magic “50 percent plus one” point, a runoff election is held. Most of the states that have provisions for primary runoffs are in the South. With a long history of one-party rule (by Democrats), the primary election was the decisive election, in that whoever won the Democratic primary was all but assured to win the general election. The requirement for a majority vote (and thus the potential for a primary runoff) was intended to encourage candidates to broaden their appeal to a wider range of voters, to reduce the likelihood of electing candidates who are at the ideological extremes of a party, and to produce a nominee who may be more electable in the general election. Now that the South is solidly Republican, the same issues still hold true.

The winner of the first round of primaries wins the runoff about 70 percent of the time, according to recent research. That’s not always the case, though. Incumbents who face a runoff are successful only 56 percent of the time; the theory is that they must be wounded in some way to have brought out two strong challengers in the primary.

While primary runoffs ensure that the ultimate winner has a majority of votes, they can be problematic. First, states usually pay for primary elections, and the runoff is just about as expensive to run as the original primary.

Second, primary runoffs typically have a drop-off in voter participation. Research from Professor Charles Bullock III from the University of Georgia found that runoffs attract 20 to 30 percent fewer voters in many states. Alabama is an exception—runoffs in the Yellowhammer State attract more voter participation than the original primary. Bullock’s research also indicates that runoff voters may be less representative of the district’s preferences.

Third, timing matters. Is there sufficient time between a primary election and a runoff election for election administrators to get ballots prepared, especially for absentee voters such as military and overseas voters?

Legislatures should consider whether majority vs. plurality winners is an issue in the state, and if so, the method to best address the problem.

For these reasons, some have suggested instant runoff voting, or ranked-choice voting, would provide a way to keep the benefits of a majority-rule system while reducing costs and avoiding the common participation drop-off. With these options, voters rank candidates in order of preference during the first primary election, avoiding the need for a primary runoff altogether.

State Action

Most states that have primary runoff elections have had these systems in place for decades. While change isn’t frequent, recent legislation has been all over the board. Some bills would eliminate runoffs altogether while others would adopt them. Still others would provide instant runoffs for overseas voters, or allow runoffs to be conducted by mail.

Alabama SB198 (2017): This newly enacted bill clarifies that only voters who voted in the original primary can come back and vote in the primary runoff.

North Carolina HB 177 (2017): This bill would have eliminated primary runoffs.

Iowa SB 483 (2017): This bill would have required a majority vote in primaries, and thus calls for primary runoffs when an election is “inconclusive.”

Texas HB 2410 (2017): This bill, vetoed by the governor, would have allowed primary runoffs to be conducted by mail.

Alabama HB 29 (2015): This enacted bill permits the state to use instant runoff elections (also known as ranked-choice voting) for military and overseas voters. Allowing these voters to rank their choices on the primary ballot may permit them to have a say in the election even if their first-choice candidate is eliminated before the runoff. Other states have moved to instant runoffs for this key segment of the voting population without needing legislation.