An important measure of success is resilience in the face of attack. If so, the achievement of the Supreme Court in Mapp v. Ohio — the decision spelling out the modern meaning of the Fourth Amendment prohibition against "unreasonable searches and seizures" — was a singular accomplishment. The Mapp decision celebrates its 50th anniversary on June 19 and conservative judicial activists, still busily trying to get it overturned, have entirely misunderstood that it represents constitutional fidelity and adherence to the rule of law at its best.
Under siege by conservatives since the moment it was decided, Mapp provided for the first time that the exclusionary rule—barring evidence seized without a search warrant —applied to state prosecutions. (Like all provisions of the Bill of Rights, the Fourth Amendment applies only to actions by the federal government, unless the court has "incorporated" it through the 14th Amendment's due process clause.) Today, the assault on Mapp continues, led by the current Supreme Court's conservative bloc. But that attack is misplaced, given that the opinion, written by the moderate Justice Tom C. Clark, offers a model for how true conservatives should apply the broad language and meaning of the Constitution.
Mapp v. Ohio was the first of several important criminal procedure decisions emerging from the judicial ferment known as the Warren Court, which would make history in Chief Justice Earl Warren's first year, 1954, with the landmark Brown v. Board of Education.It was not until the 1960s, however, that the court would launch what became a due-process revolution, blazing a path of progressivism that reshaped individual rights in this country—and unleashing the wrath of conservatives who charged the justices with making, rather than interpreting, the law.
Mapp was arguably the most controversial of the decisions protecting the rights of accused criminals, although it didn't start out that way. Acting under what they said was a tip from an informant, police officers went to the Cleveland home of Dollree Mapp, a single mother of mixed black and Cherokee Indian parents, and demanded entry to the home to search for a local bombing suspect. The police didn't produce a warrant and Mapp, on the advice of her attorney, told them they could not enter. More police arrived, eventually forcing their way in, searching the house, and taking the man in question into custody. They also arrested Mapp after turning up what they said was illegal gambling-related material and several allegedly obscene books and pictures.
Mapp's attorneys argued that the obscene material had been unlawfully seized and should not be allowed at trial as evidence. That legal principle, known as the exclusionary rule, had been applied in federal criminal trials since 1914. But unless states applied that rule independently, they were not required to follow it. At the time of Dollree Mapp's trial, approximately half of the states used it. Unfortunately for her, Ohio was not one of them. She was found guilty and sent to prison.
After exhausting her state appeals, Mapp faced the usual long odds to have her case heard by the U.S. Supreme Court. A claim unrelated to the evidentiary question—that the Ohio obscenity law violated the federal Constitution—did the trick. The court, after hearing argument, voted to overturn her conviction on First Amendment grounds.
That might have been the end of the story, and there would be no 50th anniversary party this month, were it not for Justice Tom Clark, who had been assigned to write the opinion. After writing a draft adopting the agreed-upon analysis, Clark found himself in a Supreme Court elevator with Justices William Brennan and Hugo Black. He suggested that Mapp represented an opportunity to make the exclusionary rule doctrine consistent throughout the nation. With their agreement, Clark assembled a narrow majority, transformed the opinion, and overturned Dollree Mapp's conviction—this time on the grounds that the evidence used to convict her had been seized in violation of the Fourth Amendment, which for the first time, was held applicable to the states.