The court went on to say that it would be impracticable for the officers to seek warrants for every vehicle searched and that to do so would eliminate any deterrent towards smuggling and illegal immigration.

"Thus, even if it be assumed that such referrals are made largely on the basis of apparent Mexican ancestry, [Footnote 16] we perceive no constitutional violation.

As the intrusion here is sufficiently minimal that no particularized reason need exist to justify it, we think it follows that the Border Patrol officers must have wide discretion in selecting the motorists to be diverted for the brief questioning involved."

Justice William J. Brennan, Jr., wrote in his dissent that the decision was a radical new intrusion on citizens' rights and "empties the reasonableness requirement of the Amendment": "The scheme of the Fourth Amendment becomes meaningful only when it is assured that at some point the conduct of those charged with enforcing the laws can be subjected to the more detached, neutral scrutiny of a judge who must evaluate the reasonableness of a particular search or seizure in light of the particular circumstances.

Anything less would invite intrusions upon constitutionally guaranteed rights based on nothing more substantial than inarticulate hunches, a result this Court has consistently refused to sanction.