I thought that was what NAFTA was supposed to do for North and South America, flash your drivers and on your way. Today it is a little more complicated than that to say the least. If anybody could challenge that it would be the natural citizens of both Americas who should be able to travel just that easy. DNA scan is the identifier, can't be faked and the sample can be given by the person by whatever method they are most comfortable with. Just make sure each vehicle has a steel safe that gets a customs sticker at the border and if it is broken before you exit their country you will be going to jail and there is a 5 year waiting time until your 2 hour trial.
I would vote for something like that if the list of what you can and cannot carry in the safe is clear and the same in every location. (save the coco leaves for the mountain passes in Bolivia and not a tea break in some shack in the deep bush. (okay maybe both would be alright) That is the next point, would a common classification bring more freedoms to all citizens or would some lose what are freedoms right now? That would make a huge impact on how I would vote on such a change.
The guy with an Igloo and the guy with a grassy roof both have the right to read the same discussions real time and the devices are there, they just need to be classified as necessities rather than toys of the elite.
Well, since here we're not talking about a common nation, government and laws, but just a common citizenship, it would mean local and national laws apply, just as a Canadian in Ontario abides by Ontario law and a Quebecer by Quebec law. The plus though is that anyone can choose to reside where he wants to reside, and benefit from the full rights of citizenship in that location. However, the applicable local and national laws of where he resides would still apply.