votesplitting

Votesplitting is a voting phenomenon in which voters who prefer similar political platforms or candidates divide their votes among multiple contenders. In elections that use single-member districts with plurality voting—the winner is the candidate with the most votes, not a majority—this division can prevent any one preferred candidate from winning even when a majority would support that broad position.

The effect is most visible when several candidates with overlapping agendas run in the same race. If their supporters split their ballots across these candidates, a rival with a different platform may win with only a plurality. This dynamic is often described as the spoiler effect, and it can discourage voters from choosing their preferred candidate if they fear helping a less desirable option win. The phenomenon can also produce “wasted votes,” where votes for a non-winning candidate seem to have little impact on the outcome.

Examples commonly discussed in political analysis include several U.S. elections where third-party or minor-party candidates drew substantial support from voters who might have preferred one of the major-party candidates with similar views. The precise impact of vote-splitting is debated and depends on voter behavior and electoral rules.

Mitigation strategies include ranked-choice voting (instant runoff), which transfers votes from less-preferred candidates to next preferences, and runoff elections, as well as moves toward proportional representation. Other approaches include threshold rules or fusion candidacies, though these have varying political and practical implications.