Oh, but that could be used for voting and we don't want that.
It would give the federal government inappropriate control of state elections.
I don't know how many times this needs to be iterated, but voter ID has absolutely nothing to do with election security. It has everything to do with voter suppression, just like poll taxes and literacy tests. It gives poll workers discretion to turn people away.
There's a reason this idea is pushed solely by Republicans with the explicit goal of reducing the number of people who can vote, because fewer people voting is better for Republicans.
I can see another group getting very upset "They want to see my what before letting me buy a gun!"
Voter ID changes would be a lot easier to swallow with a free national id that you don't have to register or fill out paperwork to get.
Maybe add in automatic voter registration to sweeten the pot?