Might be doable for planes, trains and buses but not motor vehicles.
Would truckers be exempt? If not, how many would quit?
How many roads cross state lines? How many people would it take to man the checkpoints 24/7?
How many people cross state lines as part of their daily commute?
I have 4x4. Are they going to watch every power line, every field, the woods?
This seems impractical, unless they want to turn America into a police state.
Passports for interstate travel?
Many big cities are on state borders, with millions traveling back and forth every day.
Will there be border checkpoints between New Jersey and New York City?
Between Philadelphia and New Jersey?
Between Washington DC and Maryland and Virginia? And also between the Virginia suburbs and the Maryland suburbs of Washington? Will the Capital Beltway become permanent gridlock?
Between Cincinnati and its Kentucky suburbs?
Between Louisville and its Indiana suburbs?
Between Kansas City Missouri and Kansas City Kansas?
What about that town, Bristol Virginia and Tennessee, where the state line is a street running through the middle of town? In that case, simply crossing the street you will be in another state. Will there be border guards at every crosswalk across the street? I know how absurd that sounds, but such pedestrians would be involved in interstate travel.
I remember a week after 9/11...we went on a driving vacation thru western Canada...decided to use a remote crossing from somewhere in western Montana...was double manned...first we went thru US border agents, then 50 feet further we went thru Canadian agents...out in the middle of nowhere...and now with drones...our overlords can probably watch all those roads, etc.