The Supreme Court agreed yesterday to decide the constitutionality of an increasingly popular tactic used by police in the war on drugs -- boarding buses and trains and asking to search passengers' luggage without any reason to suspect they are carrying drugs.

Handing down orders shortly after David H. Souter was sworn in as the 105th Supreme Court justice, the court said it would review a Florida Supreme Court decision striking down the practice as a violation of passengers' rights to be free from unreasonable searches and seizures.

The 51-year-old Souter took an oath to "do equal right to the poor and the rich" and then assumed the seat reserved for the junior justice, on the far right of the courtroom, to hear oral argument in cases involving takeover battles, federal pension law and jury selection. Justice Thurgood Marshall, who said at the time Souter was nominated that he had never heard of the New Hampshire judge, shook his new colleague's hand after Chief Justice William H. Rehnquist welcomed him to the court.

Souter did not participate in the decision to hear the bus search case, which the justices voted to review at their conference Friday.

The federal appeals court here heard oral argument last month about a similar practice by the District police department's narcotics interdiction squad. The department halted random questioning on board buses following lower court rulings finding the searches unconstitutional.

In the case the court accepted yesterday, Florida v. Bostick, police in Broward and Palm Beach counties randomly boarded interstate buses and trains during scheduled stops and announced they were engaged in drug interdiction. The police then asked to search certain passengers' luggage and advised the riders that they could refuse consent.

The state of Florida argued that drugs found under such circumstances are the product of "consensual encounters," not the result of seizures covered by the Fourth Amendment.

But the Florida Supreme Court said that given the circumstances of the case -- in which officers wearing raid jackets, carrying guns and blocking the exit asked to search a passenger's bag during a layover in Fort Lauderdale -- the passenger would not have felt free to leave, and Fourth Amendment protections were thereby triggered.

Since the Fourth Amendment applies, the court said, the policy violates passengers' constitutional rights unless police have some basis for suspecting illegal activity, the court said. It added that consent obtained under such circumstances is not voluntarily given.

"Roving patrols, random sweeps, and arbitary searches or seizures would go far to eliminate such crime in this state. Nazi Germany, Soviet Russia, and Communist Cuba have demonstrated all too tellingly the effectiveness of such methods. Yet we are not a state that subscribes to the notion that ends justify means," the Florida court said.

One of the dissenting justices agreed that the practice of bus boardings may be "distasteful," but added, "The entire war on drugs is distasteful and society should accept some minimal inconvenience and minimal incursion on their rights of privacy."

The state of Florida, noting "the importance of the issue to national drug interdiction efforts," asked the court to hear the case, arguing that the Constitution "does not prohibit consensual encounters between police officers and citizens" on buses and trains.

"Because of geography and other factors, Florida is a major pipeline for illegal drugs and, thus, a particularly critical area in the nation's, and especially Florida's, efforts to combat drug smuggling," the state said. The decision, it said, "severely restricts the ability of police to interdict illegal drug shipments in public transportation facilities."

In other action yesterday, the court:

Agreed to decide in Hernandez v. New York whether a Hispanic man's rights were violated when prosecutors used their peremptory challenges to exclude Hispanics from the jury in his trial. The prosecution said it acted because there was uncertainty whether Spanish-speaking jurors would "accept the interpreter as the final arbiter" of what was said by Spanish-speaking witnesses.

Let stand a ruling requiring a Pennsylvania high school to rent its auditorium to the Campus Crusade for Christ.

Staff writer Tracy Thompson contributed to this report.