Based on population shift over the past few decades, Vermont has drawn a lot more artisan and NY vacation home types; Maine has had a huge influx from MA, CT, and NY from Kittery to Freeport.
I foresee negative shifts in attitudes toward guns in both VT and ME if that trend continues.
NH is rocky, heavily forested, and has some of the worst wind chill factors in the northeast. It tends to attract true outdoors types, as opposed to rich city people who want a country place. I expect NH politics to remain pro-gun for the foreseeable future, although VT is currently great for guns, too.
I was raised in Maine, and I do not like the way the state's character has shifted since the 70's.