If California alone rolled out a smartcard ID, how many banks would implement support for it? And what would happen to customer when they move between states?

If California alone rolled out a smartcard ID, how many banks would implement support for it? And what would happen to customer when they move between states? California would probably be the greatest likelihood for success in this, but a big reason banks use other factors for identify verification is that those other identifiers work for all of their customers across state lines.