Are those international borders? In any case, what IS, in your judgement, the point of NYC, California, or Wales, especially wrt to popular sovereignty and democratic accountability?

What would be the point of international borders and sovereign territories, then?

You should reconsider. The intended destination regions, officially and unofficially restricted the free movement and settlement of free non-white persons. The Great Northern Migration was "allowed" in favor of the desired Great Western Migration.

On a related topic, before the 1924 National Origins Act, during the allegedly unrestricted immigration era in the USA, was there actual unrestricted internal migration in the USA, especially of non-white free persons? Even post CW Amendments, during and after Reconstruction.

Fair. What is your operational definition of "open borders", with all due precision?

So, in your judgement, going forward, the case in favor of unrestricted, unmonitored, unrecorded, immigration across any and all administrative/political borders for the US applies just as much elsewhere/everywhere, correct?

Are you claiming no "loss of generality" in your use of the USA as your exemplar?

A phenomenon consequent on the acquisition & consolidation of sufficient infrastructural & despotic power by a sufficiently large number of states to effect, also, that dimension of sovereignty over 'their' territory. "Open borders" as a sovereign policy =|= infinitely permeable (non) borders.

Transgression and Punishment

I have one already. I find bluesky incredibly boring and unbearably Euroatlanticist and "blue" (good lil normie Democrat).
YMMV.

I mean, yes I would like evidence that fishing was the number one voting issue for 43% of old guys. You think its a gotcha that I think there should be evidence for an argument? Let alone one that had no basis before it was constructed by a well funded propaganda campaign in real time?

The Eagle of Aztlán flag would be awesome.

What sort of nonsense is this? Why the heck should we send more equipment to the Bandera-loving a-holes in Ukraine?

In all honesty, using the official flag of a U.N. member state as a marker or symbol of one's humanity or ancestry or ethno-national identity is problematic.