>>105021716America doesn't have a true national ID like other countries. The closest things we have are passports (which most of us don't have), social security numbers (which aren't good for identification at all), and state level drivers licenses and IDs. The latter can often be expensive or overly time consuming to obtain (if you've ever been to a DMV you know what I'm talking about). This means many poorer individuals go without those IDs entirely.
Additionally, simple game theory should show that the main problem a voter ID is meant to fix, voter fraud, doesn't make a ton of sense. You would need a *lot* of fradulent voters to sway an election, enough that it could only be cost effective if the election was going to be close. But a close election is also where you get the most scrutiny and where fraud is likeliest to be discovered. And in reality, investigations into voter fraud typically only find examples in the single digits.
If someone is cheating at an election, it's not going to be by bussing in illegals or whatever, it's going to be by manipulating the process at a higher level. Ballot stuffing or purging voters or what have you.