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.
There's not really a big push for gun control in NH, but public opinion on many other issues seems to be gaining momentum towards the left. The problem is that many of the pro-gun politicians tend to be on the wrong side of those other issues, which jeopardizes their long term career prospects in this state. If NH ever has it's own equivalent of Newtown, I wonder if there will be enough pro-gun politicians left to contain the fallout.