That is whole or in part participle to the fact of you being in a condition that would cause any enforcement agency to stop you. Drive the speed limit. Be valid in insurance, license, etc. etc.
Wrong.
Southern Arizona has many Border patrol checkpoints. You will stop there.
Plus they may stop unknown vehicles near the border to see who or what is in there.
Reservation police have been known to have DUI checkpoints for obvious reasons. You will stop there.
Both may or may not ask about firearms.
How is that for a start?
As I stated Arizona is number one, but there are caveats