How did gay marriage happen in Massachusetts first?

Massachusetts led the nation and in some respects the world on marriage equality. It was not until June 2015 that the United States Supreme Court legalized same-sex marriage in all 50 states. Today marriage equality is recognized in countries across the globe, from Ireland to Australia, South Africa to Uruguay.

But that’s not the first occasion in recent times that Massachusetts has led the nation. In 2001, Boston Globe reporters led the nation and the world in exposing the sexual abuse of children by clergy and a massive coverup in the Catholic Church. Readers who have seen “Spotlight,” the movie about that powerful Globe series, will recall that one of the first of many challenges facing the Globe reporters was to persuade a Massachusetts judge to “unseal” court documents relating to child sex abuse cases so its reporters could report the full story and its readers could assess the facts.

The cases were assigned to Superior Court Justice Constance M. Sweeney. Who is she? “Irish Catholic," says one of the reporters in the movie, with the plain concern that Justice Sweeney would side with the Church. She did not. She ordered that documents of accusations against dozens of priests be made public — documents that dramatically confirmed the abuse and coverup.

What do Goodridge and “Spotlight” have in common?

Massachusetts residents often turn to the courts to secure rights guaranteed to them in the Massachusetts Constitution. For our system to work, judges should never decide a case because of political pressure, or because the judge knows that a particular outcome will be popular or unpopular, or because the judge wants to please the governor who appointed her. This is the law, for the Massachusetts Constitution commands that judges be “as free, impartial and independent as the lot of humanity will admit," to call them as they see them.

Certainly, in any controversial case, such as gay marriage or a decision to go against a powerful institution, judges are well aware that their decisions might be criticized or worse. So how do we ensure that judges do not look over their shoulders before deciding a case?

There is no perfect system, but some mechanisms work better:

• First, judges should be appointed only if they are qualified to do the work.
• Second, make sure that a judge who issues a controversial but legal decision is insulated from removal.
• Third, provide that judges who engage in misconduct can be disciplined and even removed for serious misconduct.

Be proud of our Commonwealth: Massachusetts does well in all three respects. Our Constitution provides that judges are appointed by the governor, subject to the consent of the Governor’s Council, a statewide elected body. But in an even better process, for many decades each Massachusetts governor has established by executive order some form of judicial nominating council, a diverse body that screens all judicial candidates before their names are submitted to the governor. Only qualified lawyers make it to the bench.

The state’s constitution requires that Massachusetts judges be eligible to serve until age 70 — a single lengthy term with no requirement of reappointment. By contrast, Iowa requires judges to run for “retention" in order to keep their appointment. After Iowa’s Supreme Court ruled unanimously in favor of same-sex marriage, three of its five justices faced retention elections the following year. All three were removed following massive campaigns by national groups opposed to same-sex marriage. What will be the next decision to lead to the removal of Iowa’s judges?

To guard against judicial misconduct, the Massachusetts Legislature established the Judicial Conduct Commission to which any person can file a complaint against a judge. Since its establishment, the Commission has disciplined various judges and the performance of all Massachusetts trial judges is regularly evaluated in a system established by the Supreme Judicial Court.

Judicial independence is a cornerstone of our constitutional democracy. For the past 240 years, governors, the Legislature, and the people of Massachusetts have worked together to build a system of judicial selection, tenure, and evaluation that best ensures that every judge can be as impartial as humanly possible.

How good is it? Justice Sweeney continued her distinguished judicial career and retired this month when she turned 70. Of the four Supreme Judicial Court justices who voted in favor of gay marriage, one was nominated by a Democratic governor and three were nominated by Republican governors; none was removed from office.

As we start this new decade, let’s acknowledge the wisdom of Massachusetts’ constitutional founders who blessed us with a judicial structure that endures.

Margaret H. Marshall is a former chief justice of the Supreme Judicial Court and author of the Goodridge decision. Send comments about this story to ideas@globe.com.