I write a lot about controversial subjects on the politics beat, but Tuesday’s story on a Maine congressional race that will be the first in US history decided by ranked-choice voting (unless a court stops it) garnered more reader e-mail than usual.

Many thoughtful readers had good questions. Other thoughtful readers did not seem to understand ranked-choice voting. So let’s step back and clear a few things up.

First, some quick background about the process.

Over the course of the last three years, Maine voters, the Legislature, and the courts have all weighed in several times on whether theirs would be the first state to use the ranked-choice voting system for primaries and general elections.


The state Supreme Court previously ruled that using ranked-choice voting for state general elections like governor and the Legislature was unconstitutional, so it was only in effect for Maine’s federal races — two House districts and a Senate seat.

How does ranked-choice voting work again?

Those of us in the nation’s other 49 states went into the voting booth and voted for one person for a particular office. If there were more than two candidates, the winner was the person with the most votes.

Ranked-choice voting, however, allows voters to rank candidates in their order of preference. If there are more than two candidates, then the ballot will allow a voter to pick a third choice, fourth choice, and so on. Voters can also just pick a first choice and be done with it.

If a candidate receives at least 50 percent of first-choice votes, than that candidate is declared a winner — and it’s basically like every other election. Last week in Maine, US Representative Chellie Pingree and US Senator Angus King won their reelections, with 59 percent and 55 percent, respectively, despite multiple challengers.


But in Maine’s Second District, no candidate received 50 percent of the vote. Ranked-choice voting kicked in: All of the ballots were brought to a central location, and the candidate who finished last will be eliminated from the competition. Those who voted for that eliminated candidate will have their votes allocated to their second choice.

This process continues until a candidate has 50 percent of the vote.

What’s the point of this system?

Supporters of ranked-choice voting believe it’s a better way to elect a candidate who best represents the will of the people.

For example, outgoing Maine Governor Paul LePage was elected and then reelected with less than 50 percent of the vote. This means that a majority of people did not choose him. Most believed that Democrat and independent candidates in those elections were closer politically, and if there was ranked-choice voting their combined vote was more reflective of the will of the people.

Indeed, LePage’s election is the reason why some supporters saw so much momentum in Maine to become the first state to pass ranked-choice voting.

So what’s happening with Maine’s Second District race?

More than a week after Election Day, no one has been declared the winner. Republican incumbent Bruce Poliquin has 46.3 percent of the vote and Democrat Jared Golden received 45.6 percent, with two independent candidates splitting up the remaining 8.1 percent.

The ballots were collected in Augusta and are being fed through a computer to tabulate the second round of voting.


If Poliquin is ahead, why did he sue the state to stop voting?

An analysis of exit polls by the Bangor Daily News, Colby College, and Fair Vote found that while Poliquin led the first round, Golden might be the second choice of those who voted for the independent candidates. This means Golden could win.

On Wednesday, Poliquin and other Republican activists filed a lawsuit in federal district court to stop the vote under the premise that ranked-choice voting violates the US Constitution. When the judge didn’t rule right away, Poliquin filed a temporary restraining order making the case that voting should stop — and no winner should be declared — until a judge has a chance to figure out the underlying constitutional questions.

Didn’t a court already say that Maine could use ranked-choice voting for congressional races?

No. The Maine State Supreme Judicial Court ruled that ranked-choice voting was unconstitutional for state races in the general election. That court had no say as to whether ranked-choice voting violates the US Constitution.

How could it violate the US Constitution?

Poliquin’s team listed many arguments in their lawsuit: First, they cite a federal court ruling that suggests the Constitution says those who get a plurality for a federal race can be declared the winner. (It leaves open whether that person has to be declared the winner.)

Second, they argue that if one person votes just for one person, while another ranks all the choices, that violates the “one person, one vote” clause.


What does the other side say?

First, they said these were the rules going into Election Day, and now is not the time to be changing the rules just because a candidate may not like the outcome.

Second, Golden’s lawyers say that if the court were to rule that Poliquin won just on the first round of voting, that disenfranchises those who purposefully voted for an independent candidate knowing their second-round vote would have been used, as they were told.

Poliquin said during his press conference that it is unconstitutional for a state to mandate a winner receive a majority of votes. But isn’t that exactly what states in the south like Louisiana, Georgia, and Mississippi are doing right now with their run-offs?

No (and this was the most frequent question I received from readers.) The term run-off is understandably confusing when ranked-choice voting is often also called an “instant run-off,” but they are totally different systems, even in the eyes of the Federal Election Commission.

What’s really going on in these southern states is that they hold something called a “jungle primary” in November, when everyone from all parties is on the ballot. If no one receives 50 percent of the vote, then the top two advance to a run-off, which is really the general election.

In the situation in Maine, voters don’t go back to the polls to decide between the top two candidates. There has already been a primary and a general election campaign.


Where do things stand?

The judge is expected to rule on the temporary restraining order Thursday. Maine’s secretary of state is expected to announce the results of the second round of voting around the same time.

Have more questions?

Maine’s secretary of state will have his own “Ask Me Anything” chat Wednesday night.

James Pindell can be reached at james.pindell@globe.com. Follow him on Twitter @jamespindell.