One of the luxuries about being a one party state is that you[1] never have to think critically about the means because you always agree with the ends. Massachusetts is going to be one of the last states that has that tough discussion about reining in the enforcement arm of government because it is a) so one sided b) rich enough to paper over problems for a long time.
[1] the theoretical average citizen who holds the average beliefs about everything
FYI - Massachusetts has historically had a Democratic legislature and Republican Governor, so it's not really a "one party state", though I think your point still stands. In fact, we had a republican senator not too long ago (Scott Brown).
While yes Massachusetts does elect Republican governors and Scott Brown became a senator (mostly because he ran against a lukewarm turd) it is very much a single party state. The legislature has a veto-proof supermajority. The Republican governors are forced to come towards the center to get any part of their agenda accomplished.
Everyone knows the Speaker of the House is the most powerful politician in MA.
[1] the theoretical average citizen who holds the average beliefs about everything