You can't draw that conclusion from the numbers. Some people who move to NH are left, some right. Those here seem overwhelmingly right of center, for example.
And there is a substantial counter-flow.
From 2007-2011 over 11,000 people moved from NH to MA. Not safe to assume they are left or right leaning as a whole, either. One could postulate they are mostly young people and left of center, but there's no data to support that I'm aware of.
What I find fascinating is that the FSP project believes they only need 20,000 committed people to achieve their political goals, while with over 350,000 LCF holders in MA a lot of people here say the situation is hopeless. 350,000 people who vote in every election could take over the state.