President John F. Kennedy was one among many to remind us that America’s is “a government of laws, not of men.”

That truism underpinning our system of justice has been built into our federal and state governments since before we had either. In 1780, John Adams based the constitution of the Commonwealth of Massachusetts on the supremacy of law.

The constitutions of our federal and state governments set up legislatures to make and change laws, which suggests that while law is supreme it is not immutable. It must change. A common cause of change is the conflict between law and morality. No doubt, you have heard people say an action “might be legal but it’s not morally right.”

Tuesday will be the 90th anniversary of the birth of an American who worked as hard as anyone to align law with morality. Dr. Martin Luther King Jr.

Liberals and — I hope — moderates celebrate King’s life and works. Segregationists — they aren’t all dead yet — continue to complain that King and his followers broke the law and therefore belonged in jail. They were right. And King agreed.

The key point of the civil disobedience that King advocated was that people protesting a law that they believe is unjust or immoral must be ready to pay the price of breaking that law. That usually means going to jail to make their point.

King was and did. One of his most memorable works is the “Letter from a Birmingham Jail.” King was one of 50 demonstrators arrested during a Good Friday march (April 12, 1963) in Birmingham, Alabama, when they violated an injunction against the march.

Someone smuggled to King’s cell a newspaper story about eight white Alabama clergymen calling the march “unwise and untimely” and separating their Christian ministries from King’s. King wrote a long reply on scraps of newspaper and toilet paper and smuggled it out to his secretary, who typed it up and released it April 16, 1963.

In the letter, King cites “natural law.” Natural law theory is based on the idea that law and morality are intertwined, perhaps even identical. Morality relates to what is right and wrong and what is good and bad. Natural law theorists believe we are guided by our nature to figure out what the laws are and to conform with those laws. “Laws, not men.”

So, when laws restricting the daily lives and rights of black Alabamans appeared to conflict with natural law, the people were justified in disobeying the law.

King wrote to the eight white preachers, “There are two types of laws, just and unjust. I would be the first to advocate obeying just laws. One has not only a legal but a moral responsibility to obey just laws. Conversely, one has a moral responsibility to disobey unjust laws. I would agree with St. Augustine that ‘an unjust law is no law at all.’ A just law is a man-made code that squares with the moral law or the law of God. An unjust law is a code that is out of harmony with the moral law.”

You needn’t believe in God, though I do, to believe in natural law.

Here in Maine, 17 Black Lives Matter protesters were arrested July 15, 2016, in Portland for obstructing traffic. Some of the protesters had behaved badly against a motorist trying to drive up the street, and all accepted a negotiated punishment. The 17 paid their fines but did not fulfill the rest of their bargain, meetings with the Portland police and others over “restorative justice.”

The Cumberland County district attorney dropped the matter. She said the protesters had never intended to fulfill their end of the bargain, beyond paying the fines of $200 each. But the matter wasn’t worth pursuing.

Had King been in Portland, my guess is he would have found it worth pursuing and would have told the protesters to honor the deal they had made with the DA and judge.

We seem to be slipping away from the purest and provably effective form of civil disobedience, not by trying to change the law but simply by ignoring it.

We have just ushered out a governor (“people above politics”) who ignored referendum laws the people wrote. Medicaid expansion, using bond money approved by voters, ranked-choice voting. And ignoring the legal timeline for vetoing bills he opposed.

The last White House grown-up may have left the room. James Mattis resigned as secretary of defense over disagreements with a president given to impulse over thought. Mattis could have had in mind his boss when he said, “You cannot allow any of your people to avoid the brutal facts. If they start living in a dream world, it’s going to be bad.”

The accounts are countless of the countless times Mattis had to tell his boss that a proposed action was against the law. It wasn’t just that the president didn’t know the law — had it been bankruptcy cases, you can bet he would have known the law — but that he just didn’t care about the law or about finding out what the law might be in a given case. With Mattis gone, who will restrain the lawlessness?

We all know about, even remember, parts of Martin Luther King Jr.’s speech, “I have a dream.” He dreamed but he did not live in a dream world. He understood that you can change the law by disobeying it.

The shadow of Dr. Martin Luther King Jr. has followed Bob Neal for most of his life. He is most impressed by King’s thoughtfulness and patience.