[1] https://www.help.cbp.gov/s/article/Article-1253?language=en_...
[2] https://www.southernborder.org/100_mile_border_enforcement_z...
[1] https://www.help.cbp.gov/s/article/Article-1253?language=en_...
[2] https://www.southernborder.org/100_mile_border_enforcement_z...
>Border Patrol checkpoints do not give Border Patrol Agents carte blanche to automatically search persons and their vehicles, other than in the manner described above. To conduct a legal search under the Fourth Amendment, the agents must develop particularly probable cause to conduct a lawful search. Probable cause can be developed from agent observations, records checks, non-intrusive canine sniffs, and other established means. Motorist's may consent to a search but are not required to do so.
I'm sure that "other established means" are a very restrictive requirement if they fail to have an "observation."
Sure, they can lie about probable cause, but they would then have that evidence thrown out in any case that derived from the search. Similarly, I can kick in your door and search your house and your only recourse is violence or the legal system. The whole question here is not whether a search is possible, but whether there is any legal consequences of it.