General Discussion

like the agricultural inspection stations entering California, or the bordecr patrol interior checkpoints, seems difficult to believe, and would be extremely disrupting. But so was the supremacist court picking the president, the Senate leader refusing to even give a hearing to the other party's supreme court nominee, and so many things that Trump has done.
Of course if there was any real opposition to what Trump would no doubt characterize as a "national security measure to control terrorism" he could always declare a state of emergency and use his 178 billion dollar police force.
I'm sure that companies would be able to buy Trump placards for their commercial vehicles to let them pass quickly. And for people travelling by plane, we all go through a TSA checkpoint whether we are travelling internationally or not.

Ihre Papiere, bitte!