Ok, my historical analogy may not be accurate because as you argue, the South had more imperialistic goals than the North, but you do not dispute that the Federal Entity in Washington (FEW) acquire a decidedly imperialist bend as result of the Civil War. That reminds me of a Chinese proverb "Choose your enemies wisely, because you will become like them."
The bottom line is that FEW is an imperialist entity today, even if it came to that position via different route than my analogy suggested. So the real issue is not "how come" but "what is to be done about it."
The purpose of my posting was to start a debate of state autonomy as a viable progressive strategy to implement social changes. In this point in history, the chances of any progressive reform at the federal level are close to zero, since the FEW is nothing more than the executive committee of the corporate class. Implementing such changes at the state level has a much better chance.
The Libertarians have already figured that out, and started the "free state project" http://www.freestateproject.org/index.jsp which aims at libertarians moving to New Hampshire and taking control of the state and local government there.
I do not particularly care for the libertarian ideology, but I think that the strategy behind it is worth to be taken seriously. The idea of a "community of interest", be it libertarian, progressive, or for that matter fundamentalist Christian, taking over state governments and insulating it from the power of the FEW makes sense for at least three reasons. First, certain states already have certain ideological leanings, so concentrating collective efforts to move those leanings even further may work much better than wasting those efforts at influencing the FEW.
Thus, New Hampshire has already libertarian leanings, so if enough libertarians nation-wide relocate to that state, they will not have to work very hard to make it even more libertarian. However, that effort would be grossly inadequate to move the FEW in the desired direction. The same thing may work for the progressives, if they concentrate their efforts on a few progressive leaning states (Vermont? Massachusetts? Maryland? New York? Pennsylvania? California? Washington?).
Second, the "state autonomy" movement can bridge ideological divides and attract support of various political orientations. Thus, fundamentalist Christians will fiercely oppose any progressive or libertarian reform at the federal level, but may support a progressive or libertarian effort to gain control and autonomy for individual states, if they see it as a chance of gaining control and autonomy in "their" states. Sort of mutual back scratching, but it may work.
Third, if several different interest groups launch the state autonomy movement in several different states, this will substantially decrease the FEW's capacity to ideologically pigeon hole the movement and squash it. If the Libertarian "take over" New Hampshire, the FEW and its corporate owners will simply unleash its substantial propaganda apparatus to bad mouth the movement, and if that does not work - send in the marines. But if the Libertarians take over New Hampshire, fundamentalist Christians take over Alabama and Mississippi, progressives take over Vermont, and California will want to regain the "free republic" status - the FEW will have a much harder time to respond to these challenges of its imperial authority.
That makes this idea worthy of consideration, no? Otherwise we end up spitting on the federal juggernaut and moaning about our powerlessness.
Wojtek