Twenty years ago, concurring in Mapp v. Ohio (1961), Justice William 0. Douglas looked back on Wolf v. Colorado (1949) (which had held that the Fourth Amendment's substantive protection against "unreasonable search and seizure" was binding on the states through the due process clause, but that the Fourth Amendment exclusionary rule was not) and recalled that the Wolf case had evoked "a storm of controversy which only today finds its end." But, of course, in the twenty years since Justice Douglas made that observation the storm of controversy has only intensified, and it has engulfed the exclusionary rule in federal cases as well as in state.
Kamisar, Yale. "Search and Seizure of America: The Case for Keeping the Exclusionary Rule." Hum. Rts. 10 (1982): 14-7, 46-7.