That theory is popular, but demonstrably incorrect. If you look at the towns along the border of Mass during, say, the Benson/Lynch gubernatorial election, they were double-digit majorities for Republicans. People coming in from Mass are political refugees, not carpetbaggers.
Plus, by moving to NH and commuting to Mass, you don't decrease your taxes, you INCREASE them, because you're not only still paying MA income tax, but also the much higher NH property tax rates.
The real left-wing strongholds are in Concord, with the SEIU and other government-employee unions fighting for their goldbricking and featherbedding, and along the border of Vermont with hippie migrants.
Thanks for the info. I lived in Vermont and Mass off and on for a total of four years. The last time I was up there was 1989.