I'm only going to address your first sentence -- I wasn't talking about being allowed to literally walk in anywhere and cast an immediate vote; if you were to g

I'm only going to address your first sentence -- I wasn't talking about being allowed to literally walk in anywhere and cast an immediate vote; if you were to go to a different precinct than where your registration is you'd still have to cast a provisional ballot so that they can reconcile later and make sure that you didn't cast another ballot somewhere else. After the election, they consolidate all the provisional ballots, make sure there's only one with your name on it, and that you didn't sign the register in your registered polling place, then they should have opened it and counted your votes for Federal races. I was only talking about the "being disenfranchised" part of the original post - you have the right to cast a vote on Federal issues as long as you were registered in the state by their deadline.