That's fair enough, but the answer is not that it is all that liberal or a leader in legislation. In fact, Massachusetts has a long history of regressive laws and culture. This is the place that bought you those irrational blue laws, censorship of books, movies and strip-tease (Banned in Boston), and seems absurdly forgiving of Kennedys, Curleys, and other smiling law breakers and rule benders. ("But he's so good to his mother...")
Boston a bit and the suburbs and exurbs a lot are populated with reactionaries. Many of them hate the idea of man/man or woman/woman marriages. Too bad. The laws say otherwise.
Let's return to those chilling days of yesterday in the Massachusetts and Plymouth Bay Colonies. The governors and other political leaders didn't trust ministers and with good reason. They left England to get away from clergy helping royalty oppress them, tell them what to think, and ordering them around seven days a week.
On their own turf, the colonists let ministers preach and earn a living, but not much else. Some academic citations will follow in other posts. Meanwhile, the major points are:
- Colonial governors originally only let civil officials, like judges, perform marriages. Ministers could say a few words at a wedding but their words or presence didn't make it a marriage.
- While ministers eventually got the right to marry couples in Massachusetts, the commonwealth constitution sees marriage as a civil contract and keeps a clean separation from the church.
The relevant part of the constitution is Chapter III, Article V.:
All causes of marriage, divorce, and alimony, and all appeals from the judges of probate shall be heard and determined by the governor and council, until the legislature shall, by law, make other provision.