This assumes that the mass shootings are a problem that they’d want to solve, but it’s not since mass shootings are useful to them. They’re flashy, get lots of media coverage, and feed a sense of chaos and societal breakdown. With that, they make the case the current system can’t keep you safe, and we need an authoritarian to bring order, which they’re happy to provide.
It’s a valid question if you live in a state that will only accept forms of ID which cost money to vote. I don’t know if that’s really the case anywhere, but if it were it could presumably be the subject of a lawsuit.
With the current SC, I expect that they’d find some bogus rationale why it didn’t count, but under a law respecting court, it’d be reasonable to require such states to provide suitable IDs at no cost.