The city’s decision to use ranked-choice voting in party primaries but not in November’s general election is bizarre.

Betting markets give democratic socialist Zohran Mamdani a one-in-three chance of winning next Tuesday’s Democratic primary for mayor of New York City. If he does, it will be because primaries in New York are decided by ranked-choice voting, which doesn’t play to the strengths of scandal-tarred front-runner Andrew Cuomo.

In this system, voters are allowed to rank up to five candidates. If no candidate is the first choice of a majority of voters, the race goes to an “instant runoff.” The last-place candidates are eliminated until one candidate is left with more than 50 percent support. If a voter’s first choice is out of the running, his vote counts for his second choice, and so on. A lot of voters recall how Cuomo had to resign as governor in 2021 in the midst of scandals involving sexual harassment and Covid-related deaths at nursing homes. So some voters may rank him at the very bottom, or not at all.

Ranked-choice voting is a fiercely debated issue at the state and local level. Democrats mostly back it, although some Republicans who are angry at liberal groups interfering in their primaries or running independent, spoiler candidates in general elections have also warmed to it.

In Maine, the legislature just voted to allow ranked-choice voting in statewide elections, including gubernatorial ones (it is already used in congressional elections). At the local level, Boston has just become the ninth of the country’s 100 largest cities to adopt ranked-choice voting. Washington, D.C., will use it for the first time this year. Portland, Ore., used it for the first time in 2024. But in red jurisdictions, ranked-choice voting has had a tough road. This year, six states — Arkansas, Iowa, Kansas, North Dakota, West Virginia, and Wyoming — have banned the practice. They join eleven other states that have previously banned it.

Republicans have sometimes turned to ranked-choice voting in internal party contests. In 2021, the Virginia GOP used ranked-choice voting and selected Glenn Youngkin as its nominee for governor. Youngkin won the nomination after six rounds of counting, securing 55 percent of the delegate votes. He proved to be an effective candidate who attracted centrist voters and became the first Republican governor of Virginia in twelve years.

I remain skeptical of ranked-choice voting because anything that complicates elections can delay results and often confuse voters, therefore increasing cynicism around elections. But states’ issuing a blanket ban on the practice strikes me as going too far. The cities that have adopted it for local and nonpartisan elections have many voters who pay more than usual attention to politics, and they like the fact that ranked-choice voting ensures that whoever is elected is picked by a majority of those voting. Conservatives who believe in federalism and preserving local control of elections should also be wary of blanket bans that affect every election in a state.

An April poll by the Trafalgar Group found that, even among Republicans, a slight majority supports the idea that a majority should be necessary to elect a candidate. Sixty percent of Republicans agreed that state parties should be allowed to use a ranked-choice voting process to select party nominees. An even larger share of GOP voters want something done to address perceived gamesmanship in the 2024 elections. That year, Trump won the presidential vote in Wisconsin, Michigan, and Nevada, but Democratic Senate candidates in those states won with a minority of the vote. Liberal groups were perceived to have promoted third-party candidates. There are times when state and local governments may want to experiment with ranked-choice voting.

What we definitely should avoid is New York City’s bizarre decision to use ranked-choice voting in party primaries but not in November’s general election.

Whoever loses the Democratic primary next Tuesday can run in the general election on another party line. So, the November election could feature Zohran Mamdani as the Democratic nominee, Andrew Cuomo on a “Fight and Deliver” party line, incumbent Mayor Eric Adams as an independent, and Republican Curtis Sliwa, who during the previous mayoral election, in 2021, won nearly 28 percent of the vote. In this scenario, voters would select only one candidate, and anyone could win. The losers could all wind up in court contesting the results and reinforcing New York’s reputation for having perhaps the most chaotic election system of any American city.