How do they do any other kind of business that requires them to travel?
how do they have a job with no ID?
Again, if you are OK with some people not having to have any way to prove identity, then why not have that requirement for everyone?
I should be able to register without providing any identification, and get a registration card, and the show up to the polling place and vote, again, without ever having proved who I am.
Why not just have ballots on a table somewhere with a sign "free, take one (or 20)", if you don't need ID to vote, that's essentially what you are saying.