Voting across the United States is registered, and voter registration requires identification. In Cook County, where I vote and election judge, voters are assigned to relatively small precincts, which track votes during the day on paper and electronic ledgers. If Judy Blue comes in and votes in the morning and you try to come in and vote for her later, you won't be able to check in. If the reverse happens, Judy makes a stink and there's a process for going through the ledger and checking identification. In practice, neither thing ever actually happens: "retail" voter fraud in the United States is practically nonexistent. It's an expensive crime with stiff penalties that is extraordinarily unlikely to impact the election.

The people who object to voter ID laws don't also object to voter registration ID laws? I thought they were worried about people who never had ID, but how would they register?

It varies widely by state but registration is typically not limited to 'show up at place X on day Y with a photo id in hand'.

Instead of just assuming that requiring ID leads to better representation, shouldn't we objectively analyze what choices lead to the best representation?

Requiring ID has the obvious tradeoff that it prevents some people who should be allowed to vote from voting. Furthermore, it can potentially lead to a system where people's votes are unfairly discounted because of administrative "errors" (e.g. interstate cross-check). From the evidence I've seen those problems are more significant than double voters or non-citizen voting.

> Or that each person should only get 1 vote?

What’s wrong with just dipping someone’s finger in ink?

Many districts vote over multiple weeks and/or offer absentee voting by mail.

> Do you think voting should be limited to citizens of the country?

Oddly, I’m not aware of any state that requires you to prove citizenship to register to vote.

The voter ID requirements gather enough info so that a person can be identified, putting them at risk of fines, prison and deportation if their citizenship is challenged later on. That's not perfect but it creates an incentive to not vote fraudulently.