On Tuesday, New York City residents will vote on whether to double the number of Americans who use a new system of voting — ranked-choice voting — to elect officials.

Technically, Ballot Question 1 amends the City Charter to “Give voters the choice of ranking up to five candidates in primary and special elections for Mayor, Public Advocate, Comptroller, Borough President, and City Council beginning in January 2021.”

But practically, it would be a tremendous lift for a growing electoral reform movement that includes Maine; Sante Fe, New Mexico; Oakland, California; and Memphis, Tennessee. As the biggest city in the nation (population 8.6 million), New York City would add considerably to the users of ranked-choice voting.

As the name suggests, ranked-choice voting lets voters mark their first-choice candidate first, their second-choice candidate second, their third-choice candidate third, and so on. Each voter has only one vote but can indicate their backup choices: If one candidate has an outright majority of first-place rankings, that candidate wins, just like a traditional election.

But if no candidate has a majority in the first round, the candidate in last place is eliminated. Voters who had ranked that candidate first have their votes transferred to the candidate they ranked second. This process continues until a single candidate gathers a majority.

Most expect New Yorkers to approve ranked-choice voting on Election Day. A wide range of groups and local leaders have endorsed the reform, and it has faced little opposition. New York City has often been on the forefront of good government reforms. Its small-donor campaign finance matching system was the first in the nation, and a model for the campaign finance proposal in HR 1.

Supporters argue that ranked-choice voting can reduce polarization and divisive campaigning by changing the incentives. Instead of just competing to be voters’ first choice, candidates are also competing to be voters’ second, third, and sometimes fourth choices, encouraging candidates to make wider appeals. Ranked-choice voting also tends to encourage a more diverse candidate pool, and leaves voters feeling happier about the process, both because their vote is more likely to matter and because they can vote for their favorite candidate without worrying about playing spoiler.

Vox is covering the results live, here.

Ranked choice voting, explained

New York City may become the most populous place in the US yet to adopt ranked-choice voting, but it’s hardly a pioneer.

Twenty cities in the United States have already adopted ranked-choice voting. In 2018, Maine became the first state to adopt it for federal elections. That catapulted the reform to a national spotlight, with presidential candidates like Sens. Elizabeth Warren and Michael Bennet now championing it. Australia has used ranked-choice voting for 101 years, and Ireland has used it for 98 years.

Studies have shown that in places that have adopted it, ranked-choice voting has made politics a little less nasty. Candidates spent less time attacking each other, as compared to similar cities that didn’t adopt ranked-choice voting. Voters in cities with the system reported being more satisfied with local campaigns as a result (again, as compared to similar cities).

Ranked-choice voting has also increased the share of racial minority, female, and female minority candidates running compared to similar cities. The scholars who have studied this most closely believe more minority candidates ran because under ranked-choice voting, such candidates could reach out to other communities where they might not be the natural first choice and ask for second-choice votes.

The researchers believe women were more likely to run because under traditional winner-take-all elections, “women were deterred from running for office by … negative campaigning.” But with less negative campaigning and more cooperative campaigning, women are more likely to run. They’re also more likely to win, scholar Sarah John and her colleagues concluded.

Under ranked-choice systems, voters don’t have to try to figure out whether to support the candidate with the best chance of winning or the candidate they like best but fear can’t win. They can vote sincerely for their favorite candidate on their first choice, and then select back-up choices if their preferred candidates don’t do well. This also allows voters to express their full range of preferences, sending clearer signals than the traditional approach to voting. And in the end, more voters are likely to wind up voting for a winner. Voters prefer this kind of “preferential” voting because they consider it fairer.

No voting system is perfect. Critics of ranked-choice say the task of having to rank multiple candidates unfairly overwhelms low-information voters, and that the added complexity hits low-income minorities hardest. The editorial board of the San Francisco Chronicle last year called the process — in place for more than 15 years — “a baffling experience for many voters,” and decried a plan by two San Francisco mayoral candidates to defeat another, London Breed, by “gaming” the ranked-choice system.

However, surveys have shown no difference in understanding of ranked-choice voting between white and nonwhite voters, and more than 90 percent of voters who have used the system describe it as simple. Some studies show turnout declines among minority voters. But most likely, when properly accounting for other factors, turnout has probably remained stable, with no declines in poorer precincts.

Americans are showing greater interest in alternatives to our voting system

While some cities with ranked-choice voting have used it to combine primary and general elections or general and run-off elections (saving taxpayers money), New York City would be unusual in applying ranked-choice voting only to the primary election and not to the general election.

However, in a heavily Democratic city like New York City, the deciding election is often the Democratic primary. Because of this, the primary often generates a crowded field, which means that a candidate can win with a mere plurality — not a majority — of votes under the current rules.

According to one analysis, in the last three election cycles, almost two-thirds of multi-candidate city primary contests (64 percent) did not generate a majority winner. And in almost a third of those elections (30 percent), the winning candidate got less than 40 percent of the vote. In other words, under the current rules, candidates preferred by far less than half of their constituents get to represent all of their constituents.

Under ranked-choice voting, outcomes like this can’t happen. The winning candidate needs to earn true majority support — a plurality does not make a victory. And if no candidate gets a majority of first-preference votes, that’s when the rankings kick in, and candidates are eliminated and their preferences redistributed until one candidate has a winning majority. This ensures that candidates need to build broad appeal. A candidate who doubles down on an intense but ultimately narrow group of supporters cannot win.

If New York City adopts ranked-choice voting, it will join Eastpointe, Michigan, a Detroit suburb, as a fellow 2019 adoptee. Eastpointe agreed to switch to ranked-choice voting in June as a remedy for Voting Rights Act violations. The Department of Justice approved the new voting system as a way to help the city’s minority voters better elect their candidates of choice. According to the American Community Survey, the white population of Eastpointe is 48 percent, and the black population is 46 percent. Yet it wasn’t until 2017 that the city elected its first black city council member, Monique Owens. This year, she was elected the city’s first black mayor.

There’s more to come. 2020 is shaping up to be a big year for ranked-choice voting. Four states will use it in the Democratic primary — Alaska, Hawaii, Kansas, and Wyoming. And Maine voters will use it for the first time in the general election for president. And both Alaska and Massachusetts will likely vote on ballot measures in 2020 to adopt ranked-choice voting statewide.

So ranked-choice voting is catching on. If New Yorkers vote themselves into the ranks, it will be yet another sign of the movement’s momentum — and a growing desire among Americans to improve our political institutions.

Correction: An earlier version of this piece stated that the white population of Eastpointe, Michigan was 42 percent. According to the American Community Survey, it is actually 48 percent. We regret the error.

Lee Drutman is a senior fellow in the political reform program at the New America think tank and the author of the forthcoming book, Breaking the Two-Party Doom Loop: The Case for Multiparty Democracy in America.