> I think the US is much too large in terms of people, GDP, and land area to be efficiently governed by one entity.

I've felt that way for a while now. People need to feel they have sovereignty, so "states" should never get too large. Also, as Taleb said in The Black Swan about mergers: the lower diversity means that when one fails, it's catastrophic. Instead of 300 million people trying to decide on Red or Blue, we could have 50 states that catered to every style, much as in Europe.