Trump supporters just tried this and were in fact caught.

Nobody with sense would try, it carries severe punishment (it's a felony) for virtually no benefit to the person taking the risk, and really virtually no effect on the election either.

https://www.washingtonpost.com/news/post-nation/wp/2016/10/2...

In my experience in the US, you have a registered polling station where you are allowed to cast your ballot. When you arrive, they cross your name off the list. If I'm only allowed to vote in one location, and that location only allows me to vote once, that should prevent double voting, even if I'm not who I say I am. Or rather, I'm not going to vote twice as the same person.

Is this the case across the US?

Whether the voter registration rolls are up-to-date, that's another matter as well. And double voting is only one type of fraud.

Meta: Please do not down vote legit questions. Election administration in the USA is arcane. This is a teachable moment.

> How do you know people aren't double voting in areas that don't check IDs?

Because it doesn't fucking matter? Also going to need to see some receipts for that.