Last month the Somerville, Massachusetts City Council voted unanimously to amend its Domestic Partnership ordinance to recognize polyamorous relationships — relationships consisting of more than just two people.

The city council member who proposed the changes to the ordinances told the rest of the council, “government shouldn’t be defining what a family is, and in fact has done a poor job of it in the past,” according to minutes from June 25 the meeting.

You may recall that the push to legalize same-sex marriage began similarly in Massachusetts and elsewhere in the early 2000s, with same-sex couples receiving varying degrees of recognition through domestic partnership measures.

We have written repeatedly about how same-sex marriage blazes a trail for polygamy and how polygamists are using the same playbook that homosexual activists used 20 years ago.

There are plenty of problems with polygamy, but one of the chief problems is that it hurts children.

Time and time again we’ve seen that the best place for a child is in a stable home with a married mother and father, and that children raised in any other type of home fare worse than those raised by a mom and a dad.

Unfortunately, the needs of children don’t appear to be driving public policy in Somerville, Massachusets.