The Massachusetts Supreme Court decided that the MASSACHUSETTS STATE Constitution requires gay marriage.
The legal rule is that the Federal courts do not interpret STATE constitutions. So, from the point of view of Federal courts, the state constitution of Massachusetts requires gay marriage.
In 1968, twenty states had anti-miscegenation clauses in their constitutions. But the Supreme Court said that, regardless of the fact that all the states that ratified the Constitution and almost all the states that ratified the fourteenth amendment and had enforced anti-miscegenation laws, the United States Constitution did not allow anti-miscegenation laws.
There was NO question of constitutional intent in that 1968 decision. The Supreme Court made no pretense that they were interpreting original intent. They were making law, and they said so.
On the day that decision was issued, it was Federal law that constitutional intent means absolutely nothing. Unless you object to that decision, constitutional intent means nothing.
And no one dares to question it.
But in that case, the Supreme Court was interpreting the FEDERAL constitution. They agreed with state courts as the final word on the fact that state law banned interracial marriage, but they said the Federal Constitution overruled the state constitutions.
So the Massachusetts law stands.
The next question is whether a gay marriage performed in Massachusetts is valid in other states. The Federal Constitution requires every state to give “full faith and credit” to the acts of other states. But there is no enforcement clause in the “full faith and credit” statement. The Federal courts have consistently refused to enforce it.
The most important case relating to one state recognizing a marriage in another state was when North Carolina refused to recognize the easy Nevada divorce law. A person who was divorced in Nevada found that, according to the North Carolina Supreme Court, he was still married when he came back to North Carolina.
The Federal Supreme Court decided that the North Carolina decision was right, and that North Carolina had no obligation to recognize a Nevada divorce. So even today you can be legally married to two different people in two different states.
When a state refuses to extradite someone convicted in another state, that is a violation of “full faith and credit,” but they have done it hundreds of times.
So a gay couple is legally married as long as it stays inside the state of Massachusetts, and nothing less than a constitutional amendment is likely to change that.
My own opinion is that if you don’t want the courts to own the institution of marriage, you will have to condemn the 1968 decision first. And NOBODY has the guts to do that.