I don't believe that the majority of Americans wish to fragment their country and destroy the power and opportunites that have been built up over the 2 centurys of our existance.
Currently according to Gallup polling.
"Conservatives" Are Single-Largest Ideological Group
This is also reflected in voting results of the last several elections.
Zeek | Where Right and Left Collide: A Zeek Debate
Using these as a basis for a hypothosis, it is easy to conclude that with the exception of urban areas, most of the country is basically conservative.
Extrapolating from said hypothosis, it would be suicide for the liberals to wish to try to wall themselves off from the rest of the country as most of the resources, food and land are controlled by red areas. While urban areas create the laws and taxes for the rest of the states, if the rural areas refuse to comply or get fed up with the confiscatory taxes imposed by a remote unresponsive government to pay for things the taxpayers do not wish to fund, the urban areas are the ones that would suffer if the food shipments, tax moneys and other necessesities of life stop flowing from the countryside to the citys.
The liberals currently have a political power that far exceeds their numbers due to the prevelence of liberal control of the press, universities and unelected government positions. They have the soapbox, the schools and the way to create useless regulations to make life difficult for everyone else, so that power gives the illusion of larger importance than what their numbers would indicate.
The conservative areas of the country could in fact strangle the urban liberal areas in event of a situation such as the American Civil war as the liberal areas do not have the numerical, stratigic resources nor supplies necessary to take the rest of the country by hostile means, or enforce its law if they did control large areas. If not supported by the general populace, you have sabotage and insurrection just as the Germans found in the conquered countries during World War 2.
Countries like China would smuggle weapons to both sides to keep the fight going because strife removes a trading competator, the one country that can thwart their imperialistic designs to expand their influance, and with the US out of the equation, you would see wars across Asia Europe and the Middle east break out as countries struggled to fill the void we would leave in this circumstance.
If there is to be a revolution, the history of this country indicates that it will be done in a way to change the fundamental direction of the country by ballot, by tax moneys, by the majority rejecting the policies of the left as was seen in the 2010 elections when the left pushed too far too fast.
Segregation by political bent has always occured, just as it has by socio-economic status or nationalities.
Attacks against the basic foudations of the United States by presidential fiat, by congressional heavy handedness and by judicial activisim from the bench have caused a lot of unrest in the country as evidenced by the rise of groups such as the TEA Party and a large segement of the population voting against the incumbent party in Washington.
The fringe far left has no more power than the fringe far right, however as our founding fathers said, "Government exists through the consent of the governed". When the politicians loose sight of the job they were hired to do, they can, will, and have been fired by the people.
The vast majority of people don't worry about Don't Ask Don't Tell, or most of the other garbage flowing out of Washington right now.
They want a job, they want to provide for their families, they want to be safe from foreign people bringing crime and draining resources from their local communities.
All the chest pounding, hair pulling and name calling in the world won't change the fact that the basic American citizen doesn't care about the lofty political rhetoric, they just want to live their lives in peace.
The United States break up? Could happen, not in the near future because we have too much to loose.
Will it happen? Maybe. Times change all things and I don't have a crystal ball.
But for those formenting dissent to cause chaos so they can profit by unrest to institute their ideals must remember, A revolution needs revolutionary people, but once the war is over, they are seen as troublemakers and a threat to the status quo, and as such, are removed as a threat one way or another.
Be careful what you wish for, you may get it.