Massachusetts was the first state to legalize gay marriage
That was the doing of the State Supreme Court. As a general rule, Supreme Courts can be far removed from the voters.
Romney Care/Obama Care was literally a Republican policy designed by the Heritage Foundation in reaction to Bill Clinton's Health Care plan. It is very much a moderate/corporate policy.
Again, I am not trying to say that MA is not more progressive than the average state. Clearly it is. But it also has a lot of white working class voters who vote Dem but are not really progressive. There are many Democrats in the MA State legislature that reflect that reality. Boston and the Berkshires are not the entire state.