You could be right, but I’m not convinced it’s all that easy to vote in multiple precincts. Explain how that works and I might be more agreeable. To be honest, this has been a concern of mine in the past, but I’m not sure how realistic it is. Convince me.
I think you’ll have to convince me that it would be any more difficult than voting as an alien. In either case, you give a name which may or may not be yours, an address at which you may or may not reside, and present documents that may or may not be real or (in jurisdictions that allow it) have some registered voter whose registration may or may not be legal vouch for you.
It helps if it’s part of a large, organized effort to flood polls with more same-day registrants than workers can process with due attention.