It would cost almost 4x as much (let's say 3x as much because you don't quite need to accommodate as much volume at any one time), and elections already are pre

It would cost almost 4x as much (let's say 3x as much because you don't quite need to accommodate as much volume at any one time), and elections already are pretty expensive. It also would mean that every polling place would have to keep all of the records, ballots, etc. safe for longer. Imagine if polling places lost the records of who had voted already overnight.