It is not enough to argue, as does the Government, that the problem of deterring unlawful entry by aliens across long expanses of national boundaries is a serious one. The needs of law enforcement stand in constant tension with the Constitution's protections of the individual against certain exercises of official power. It is precisely the predictability of these pressures that counsels a resolute loyalty to constitutional safeguards. It 274*274 is well to recall the words of Mr. Justice Jackson, soon after his return from the Nuremberg Trials:

"These [Fourth Amendment rights], I protest, are not mere second-class rights but belong in the catalog of indispensable freedoms. Among deprivations of rights, none is so effective in cowing a population, crushing the spirit of the individual and putting terror in every heart. Uncontrolled search and seizure is one of the first and most effective weapons in the arsenal of every arbitrary government." Brinegar v. United States, 338 U. S. 160, 180 (Jackson, J., dissenting).
The Court that decided Carroll v. United States, supra, sat during a period in our history when the Nation was confronted with a law enforcement problem of no small magnitude—the enforcement of the Prohibition laws. But that Court resisted the pressure of official expedience against the guarantee of the Fourth Amendment. Mr. Chief Justice Taft's opinion for the Court distinguished between searches at the border and in the interior, and clearly controls the case at bar:

"It would be intolerable and unreasonable if a prohibition agent were authorized to stop every automobile on the chance of finding liquor and thus subject all persons lawfully using the highways to the inconvenience and indignity of such a search. Travellers may be so stopped in crossing an international boundary because of national self protection reasonably requiring one entering the country to identify himself as entitled to come in, and his belongings as effects which may be lawfully brought in. But those lawfully within the country, entitled to use the public highways, have a right to free passage without interruption or search unless there is 275*275 known to a competent official authorized to search, probable cause for believing that their vehicles are carrying contraband or illegal merchandise." 267 U. S., at 153-154.
Accordingly, the judgment of the Court of Appeals is

Reversed.