How Ranked-choice Voting Works

What's Different About Ranked-choice Voting
Caleb Kleppner of True Ballot demonstrates how Portland's new ranked choice voting system would work, using Wonder Woman, Garfield, Miss Piggy and Spider Man as examples for mayoral candidates. Shawn Patrick Ouellette/Portland Press Herald via Getty Images

Maine, the first state to adopt ranked-choice voting, has long been faced with a difficult problem at the polls. Because third-party candidates often have attracted significant support, nine of the state's past 11 governors have been elected with less than 50 percent of the vote, and five have won with less than 40 percent. When current Maine Gov. Paul LePage, a Republican, ran against an independent and a Democratic opponent in 2014, he managed to win, even though just 38 percent of the voters backed him [source: Grabar].

We've seen similar things happen in presidential elections. In 2000, the 97,488 voters who supported Green Party candidate Ralph Nader in Florida may have enabled Republican George W. Bush to win the state by 48.847 percent to 48.838 percent over Democrat Al Gore and claim the presidency, even though Gore won the popular vote nationwide [sources: Orman, Scher].

A ranked-choice election system is designed to prevent such outcomes. Instead of picking a single candidate, voters rank all the candidates in order of preference. When the ballots are counted, if one of the contenders gets a majority of top rankings, then we'd have a winner.

But if nobody gets over 50 percent, a runoff process would kick in. The candidate with the least No.1 votes would be eliminated, and his or her voters would be reallocated to one of the others, based on their second preferences. If that still didn't give the top candidate more than 50 percent, then the new candidate with the lowest vote total would be eliminated and his or her votes distributed to the rest. The runoffs would continue until one candidate obtained a majority. That's why ranked-choice voting is sometimes called instant runoff voting. The voters don't have to return the polls a second time for a runoff [source: Mercer].

Ranked-choice elections are a bit more complicated than conventional ones, and they require special software to tabulate the rankings and conduct the runoffs [source: FairVote]. Filling out the ballot is more complex too. But what the system really would change is how election campaigns are conducted.