It doesn't quite follow that you highlight the need for a political system to handle shifts, then suggest that amending the constitution is not such a form of flexibility, but a transformation into another country entirely.
Normal amendments are fine. The 13th, 14th and 15th amendments weren’t just any old amendments though. They were passed via a non-political means (or if you take Clausewitz’s opinion, that war is a continuation of politics by other means, it is still a non-constitutional means), effectively without the southern states’ consent.
Almost everyone today thinks the reconstruction amendments were good, but the fact that we had to fight the bloodiest war in our history to get them is not a compliment to our political process.
