We need ID to vote in Ireland (in theory; it's spot-checked), but the range of things accepted as ID are much greater. In particular, a debit or credit card can be used, as can a social security card. Since basically everyone either has a job (and thus needs a bank account) or draws some sort of social welfare, or both, nearly everyone has one of these anyway.

Most developed countries just have a mandatory ID card, of course.

The US states requiring ID would be much less worrying if they would accept something that everyone has. It's the selectiveness about forms of ID that makes the motives clear...