Why does it have to be a border shutdown? It is politicized to the wazoo in the US already.

Canada adopted a policy of mandatory 2 weeks quarantine for every inbound traveler, and if the numbers are any indication, it worked quite well (but then they went lax on some other aspects in H2 and now are seeing numbers go up again...)

Santa Clara, CA is about as democrat as they come and they've recently announced quarantine policies based on travel distance as well, so in my mind, it seems possible to de-politicize.