This was me for quite some time. I remember seeing it discussed online here and there, and farther right liberals would jump in and point out that open borders and a united federal government basically are what allow the treats to flow, and how quality of life in any seceding region would decline rapidly of such an attempt were to be successful. They weren't wrong or anything, it's just funny how poor of an instinct educated-working-class left-liberals (including my former self) usually have for ecenomics.