NH can be roughly broken up into four voting groups.
Native Libertarians - Anti-tax and not much else. Tend to be moderate to liberal social issues if they have to choose. Can be swayed towards a dem if the Democrat is seen as not insane and otherwise ok with taxes being low in the state. (for example being alright with, Gov. Lynch) These folks are peppered around the state and appear in great numbers in areas not dominated by the other groups.
Vermont Bleed Over Liberals - Basically the folks that make Vermont so heavily dem. Progressive social issues tend to dominate these folks but they're also pretty progressive in economics as well. Not all of them come from Vermont, but some are generic college kids and young professionals. As one of these myself, I can say that for us its more an issue of motivation and turn out then it is swinging one way or another.
Older Boston Exurbanites - Taxes were too high for them in Boston or anywhere south of the boarder, so they took the opportunity to join the old school libertarians in NH while still having most of their work attached to the greater Boston area in some fashion. As time as moved on, that attachment has weakened and the relative halo has expanded north. They tend to be socially moderate, anti-tax, but also like social services like plowed roads. They also have money to pay high property taxes and the like so they're ok with such a setup. Usually vote rep unless faced with a loony. Have been edging towards tea land of late thanks to the appearance of the next group.
Newer Boston Exurbanites - Taxes are less an issue for these folks, but it is a factor as cost of living is what drives them across the boarder. Lean apolitical overall or moderate, they're probably the nearest the state has to a true swing group. Not as keen on the property taxes as the Older Exurbanites, they'd be ok with lower property taxes and income taxes instead. Especially as most of these folks are still bunched up by the boarder and can easily work in Boston anyway. They're more in tune with Mass. in terms of social issues but not as fervently as the Vermont bleed over group. Lean dem overall but can swing a great deal depending on how a campaign goes.
If the newer exurbanites and vermont bleed over are motivated and going dem, and the other two groups either demotivated or the rep's put up a crazy candidate, a Democrat wins here. That's how Lynch has been doing it. That's how Obama did it in '08 (McCain became unacceptable to the old guard as tax policy doesn't matter if you don't know how to handle the economy, vermont bleed over was motivated and the new exurbanites were appealed to).
At present, Romney is the one in the best position to solidify the old exurbanites and to keep the new exurbanites split. Obama's pretty much lost the old libertarians and has to hold the vermont bleed over to have a chance. If Romney isn't the nominee, the new exurbanites can swing Obama heavily and depending on which nominee it is and how their tax plans hold up, the other two right leaning factions can be split or depressed.
what I find interesting is how they elected someone like Bob Smith or Norris Cotton. Both of whom qualify in my book as pure nutters. Cotton was the only NE Republican (and only one of six republicans overall) to vote against the civil rights act. Bob Smith was only one of three senators to vote against Ginsburg in 1993. You would think the republicans would be like the George Aikens, Olympia Snowes, Ed Brookes in surrounding states.
