My answer is yes. The more we centralize powers that used to be local, the more we end up in this winner-take-all thing we have going on, where rules are made in a one-sized-fits all manner. That's bad for a multitude of reasons. As much as possible, distributed, self-optimizing systems out perform command-and-control systems. (But not always. When that paradigm doesn't work, the fallback should always be a federated, staggered and layered system)
Note that true democracy begins failing as soon as you begin leaving a small social group. By the time you get to the Dunbar Number, it's already failed and you have to move to some kind of representative system.
Even representative systems fail, however, and for the same reason: human social interactions don't scale. So you might get to a Dunbar Number squared level, and decrease the feedback time, and make it work up to half a million or so.
That's city or borough sized. From that point outwards it's just partisan power plays -- then you're really looking at how organized groups act -- which is a good reason to limit power more and more the larger the scale.
My tangent aside, to answer your question, I think it would be no. Any happiness increase of the people living in the new United State(s) will surely be negated by the huge pain and suffering required to create them. If you discount that, the answer to that is also probably yes.
[0] https://news.ycombinator.com/item?id=13468508
[1] http://www.citylab.com/design/2011/10/urban-rural-happiness-...