No one does. As far as registering to vote goes, you don't do that 24/7. You do it once in years usually.
Who can vote in elections has changed over time. In America, when first formed it was usually just landowners that could vote. Then free men, etc. So?
So? Daley's 'Chicago Machine' ran into the 1970's and was a poster child for vote fraud and corruption. The point I'm making, and it is fully valid, is that voter fraud and corruption are possible on a wide scale today and we shouldn't be doing anything that could further it. Lack of voter ID is clearly a case in point.
How would you detect voter fraud in a system that is set up specifically to make such detection difficult or impossible? For example...
If you have a system where voter registration doesn't require ID, then voting doesn't require ID, and on top of that voting is done by mail-in ballots that are not supervised in any particular manner. Toss in that political operatives can go around and collect said ballots to turn them in. Now, toss in that voting goes on for weeks and weeks and that votes are counted in the same way, even after the specified date for the election to end comes around.