Yes but since the State SC interpreted the State Constitution as allowing gay marriage (would have loved to see that run up the flag pole in 1700) the Amending the Constitution is needed requiring a mjaority of both houses in special session in consecutive years.
In Oklahoma an initiative petition goes up to the people for vote, the legislature cannot stop it. If approved, then it ammends the constitution. It appears that MA does not trust the people to ammend the document that governs them.