Political gamesmanship and the spoiler effect prevent majority winners in some of the Treasure State's most impactful elections.

As in most elections, Montanans have a lot of important priorities to consider this November. One contest in particular, though, is receiving outsized attention: control of the US Senate may hinge on the outcome of the race between incumbent Democrat Jon Tester and Republican Tim Sheehy. In this race, two other candidates are drawing the attention (and ire) of the major parties. Earlier in 2024, the Montana Democratic Party lost a lawsuit to remove Green Party candidate Robert Barb from the US Senate ballot. And former president Donald Trump personally put pressure on Libertarian nominee Sid Daoud to drop out of the race and endorse Sheehy.

Partisan jockeying over candidates with virtually no chance of winning is not uncommon in the United States and should be familiar to longtime observers of Montana politics. The more competitive a race, the more third-party candidates matter. Partisan primaries present a similar problem: crowded fields of candidates can split the vote, sending a nominee with minority support from their own party to the general election.

In 46 primary and general election contests from 2012 to 2022, state and federal officeholders in Montana won only plurality support (more votes than any other candidate but less than 50 percent of the vote). In other words, a majority of voters preferred other candidates to the actual winner.

The plurality winner problem conflicts with the principle of majority rule, a core tenet of democracy. It also encourages the major parties to amplify divisions among voters and spend valuable resources propping up or undermining minor-party candidates to spoil an election for their competitors.

Other states, including Alaska, Georgia, Maine, and Mississippi, have implemented systems that guarantee majority-winner elections. Two measures on November's ballot would do the same in Montana.

Montana plurality winners by the numbers

Sightline examined more than 2,000 Montana elections between 2012 and 2022, including all statewide races for governor, lieutenant governor, attorney general, secretary of state, state auditor, and superintendent of public instruction, along with senators and representatives at the state and federal levels.1 Altogether, the inquiry covered 2,163 races (780 general elections and 1,383 partisan primaries) over the decade. It revealed that:

In 94 percent of races, only one or two candidates were on the ballot, guaranteeing a majority winner.

Multicandidate races are most common at the congressional and statewide levels, as more than half of Montana's congressional races from 2012 to 2022 had three or more candidates.

Few state legislative contests attract more than two candidates, as plurality winners prevailed in only 2 percent of the 2,077 elections for state house and state senate.

However, some of the most consequential state and federal general election contests produced plurality winners, with winning candidates receiving less than 50 percent of the vote in elections for US Senate (2012), Montana governor and lieutenant governor (2012), and US House (2017 and 2022).

In ten partisan primaries for statewide or congressional offices, nominees who did not have majority support from their own party moved on to the general election.

All told, a majority of voters cast their ballots for someone other than the winning candidate in 26 percent of congressional races and 9 percent of statewide races.

The majority of Montana elections produce majority winners. But plurality winners are most common in high-profile, high-impact statewide and congressional contests.

Notable among the plurality-winner contests were Democratic US Senator Jon Tester's general election in 2012 and Republican US Representative Ryan Zinke's bid for Montana's First Congressional District in 2022. In both instances, a majority of voters split their vote between the nom...