A side effect of this is something I have also pointed out many times. US Customs and Border Patrol claims very wide latitude in violating Americans' constitutional guarantees within the 100-mile border zone (in which I have lived, most of my life).
As a person who is frequently mistaken for Latino/Hispanic/Chicano, if they decide to harass me, no amount of documentation is a shield, because they can simply claim that my documents appeared to be forged or make up some other unfalsifiable lie.