One cause of the disparity in polling places was section 5 of the VRA. Any changes to polling places that impacted covered minorities were subject to preclearance or judicial review just like redistricting. Many covered states chose to leave them unchanged, even as voting populations grew, rather than deal with the feds. Now that section 5 is inactive those disparities should be open to challenge under section 2, particularly after the precincts are redrawn due to the 2020 Census.
This may be naive, Muon, but surely plans to expand voting locations and machines in minority-majority districts would likely sail through fed review relatively easily? I mean, it is the feds, but still.
I would think so, too. I suspect that the states in question didn't want to open the whole question of precincts and polling places, so the easy course was to make no changes unless ordered to do so.
