by the Center for Voting and Democracy
Most U.S. elections are held under plurality voting rules in which the candidate with the most votes wins. If three or more candidates run in the race, then the winner can have less than a majority of the vote. But the question always arises: was that winning candidate really preferred by most voters?
Instant Runoff Voting (IRV) is a sensible reform for elections where one person wins. Examples include elections for governors, mayors, legislatures using single-seat districts, and US president (for allocation of Electoral College electors). Instant Runoff Voting is better than plurality elections because:
IRV is also better than "two-round" runoff or primary elections, which often result in a change in voter turnout between the two rounds. IRV finishes the job with one election, which means that
How IRV Works: Each voter has one vote, and ranks candidates in order of choice (1, 2, 3, etc.). The counting of ballots simulates a series of run-off elections. All first choices are counted, and if no candidate wins a majority of first choices, then the last place candidate (candidate with the least first-choices) is eliminated. Ballots of voters who ranked the eliminated candidate first then are redistributed to their next-choice candidates, as indicated on each voter’s ballot. Last place candidates are successively eliminated and ballots are redistributed to next choices until one candidate remains or a candidate gains over 50% of votes.
Voters have the option to rank as many or as few candidates as they wish—their favorite candidate first, their next favorite second and so on. Voters have every incentive to vote for their favorite candidate rather than the "lesser of two evils" because their ballot can still count toward a winner if their first choice loses. There also is every reason for a voter to rank as many candidates as they want, since a voter’s lower choice will never help defeat one of their higher choices.
IRV is used to elect the parliament in Australia and the presidents of the Republic of Ireland and the American Political Science Association. A related method is used in Cambridge (MA) for city council.
Example: In both 1992 and 1996, Bill Clinton was elected president with less than 50% of the popular vote. IRV could have been used to elect a majority-winner. Here’s how it could have worked.
|The 1992 Presidential Election—a Simulation|
|Candidate||First Choice %||Ballots redistributed
to 2nd choices
|George Bush||38%||+10%||= 48%|
|Bill Clinton||43%||+9%||= 52%|
|Ross Perot||19%||- 19%||X|
Assume that, of the 19 percent of voters who ranked Ross Perot first, slightly more than half (e.g. 10% of all voters) ranked George Bush second on their ballots, and slightly less than half (e.g. 9% of all voters) ranked Bill Clinton second. When Ross Perot is eliminated, those votes are redistributed. Bill Clinton ends up with 52 percent of the overall vote, a clear majority, and is declared the winner.