The unification of north and south in the declaration and constitution was always contentious. We had our first attempt at secession just after the war of 1812. Our next in the civil war. vast immigration and the depression that followed, disunity. The world wars created unity. The marxist/postmodern insurgency restored the original demands for secession. The reason for the original failure was fear of re-conquest by europe. The reason for the civil war failure was the profitability of the westward expansion and the threat that the industrialized north would be reduced to a marginalized minority and the west and the south the majority – and slavery is merely the primary driver by which that economic and political reality was perpetuated. The 1960s repeated the process. ANd today we are going thru it again.
The difference today is we are no longer fighting over the profitability of westward expansion, but the profitability of homogeneous territorial peoples and heterogeneous. Or stated differently “the profits from immigration as a vehicle for selling off a conquered conteintent, and the profits of selling them consumer goods, is now neutralized by the world having caught up to western technology and institutions. What the world cannot catch up to is western demographics and culture. Because as far as I know no other people are capable of it.