The Supreme Court ended its term Wednesday, turning off the spigot on a stream of decisions that greatly affect diverse elements of the population by, for example:

Presenting the gift of life to rapists on death row who welcome it, and to unborn children whose mothers don't.

Decreeing equality between elderly widows and widowers who draw Social Security survivors' benefits, and between young men and women who buy beer.

Giving constitutional protection to professionals who advertise the availability and price of routine legal services, and to vendors who advertise the availability and price of nonprescription contraceptives.

Handing a victory to a grandmother who fought an effort by a local government to break up her extended family, and a defeat to former President Nixon, who fought an effort by the federal government to control access to his papers.

Divining in the antitrust a congressional intent to immunize price-fixers from damage suits by nearly all of their victims, while divining in the 1964 Civil Rights Act a congressional intent to preserve union seniority systems that in operation - not design - discriminate against women and minorities.

Divining the intent of the court is not always easy even for its nine members, who review and criticize each other's opinions before they are issued. Take the case of a white Denver policeman who fired a fatal shot into the back of the head of a fleeing 15-year-old black.

Initially, the court granted a petition by the victim's mother for review of a decision awarding her damages of only $1,500. Then, last month, it threw out the case with an unsigned opinion purporting to be an explanation of why, in granting review, it had acted "improvidently."

The explanation left three dissenters - Justices Bryon R. White, William J. Brennan Jr. and Thursgood Marshall - "at a loss to understand the basis for dismissing the petition . . ."

On Tuesday, the court issued an unsigned opinion that might require decoding by a cryptanalyst, judging by the dissent of Justice John Paul Stevens, joined by Brennan and Marshall.

The case came from the Eighth U.S. Circuit Court of Appeals, which held that Milwaukee school officials discriminated unconstitutionally against black students. The appellate judges neither had before them nor approved a remedy.

The unsigned opinion directed the judges to reconsider their ruling "in the light of" a high court decision in a Dayton, Ohio, desegregation case that remedies must be commensurate with violations.

But the judges never having decided the proper scope of a remedy in Milwaukee, there is nothing for them to reconsider "in light of" Dayton, Stevens wrote. Thus there is "no justification" for them to nullify their judgment of a constitutional violation, and they remain free to re-enter it, Stevens said. He termed the high court's action - taken on the next-to-the-last day of the term - hasty."

Unhastily, in January, the court ruled 6 to 3 tht state laws - not federal common law - government ownership of certain lands that had been a riverbed. This was a reversal of a 7-to-1 decision made barely three years earlier.

Rather than being unfathomable, the reversal sent a clear and important signal: a court majority - frequently led by Chief Justice Warren E. Burger or Justice William H. Rehquist - was absolutely bent on following up and consolidating major trends begun by explosive rulings in prior terms, much like infantrymen moving in after a bombardment.

As the reversal in the riverbed case indicated, one of these trends is to defer, whenever possible, to the states rather than to the federal government. Marshall, in a dissent joined by White, suggested that the majority was willing to carry the trend very far.

It made "no . . . effort to inform itself about the impact of its ruling on the federal government," he wrote. "Indeed, the majority opinion [by Rehnquist] does not even consider that issue, although it is normally central . . . The only views the court has received are those of . . . states, whose interests here are hostile to those of the United States."

The riverbed decision tied into a related trend: denying access to federal courts. This, in turn, fitted into a larger pattern of restricting judicial power to shape the outcome of certain sensitive social issues that can be left to the political process, such as abortion and school desegration.

Until a few months ago, rulings shutting off access to federal courts mainly have affected prisoners, minorities, consumers and the poor. But in April, the justices voted 5 to 4 to add a new class: schoolchildren who have been disciplined with corporal punishment regardless of its severity.

The case involved two 14-year-old junior high school students in Miami, one of whom said he was beaten "so bad I had fever and couldn't sit right for two weeks."

For such victims, state remedies - including criminal prosecution and civil lawsuits - are available. Justice Lewis F. Powell Jr. wrote in the opinion for the court. They do not have the constitutional protection against cruel and unusual punishment, he said. Joining him were Justices Potter Stewart. Harry A. Blackmun and Rehnquist, and the Chief Justice.

But particularly when states collided head-on with the First Amendment or other clean-out constitutional or federal authority, they often lost.

In an 8-to-0 ruling for example, the court held that a state hoping to inhibit "white flight" cannot do it by banning real estate "For Sale" signs. Similarly, the court held:

That a state trying to promote an ideological message such as New Hampshire's "Live Free or Die" cannot do it by forcing persons to display it on their cars or other private property.

That a state judge cannot order the press to conceal the name of a juvenile identified in public judicial proceedings held in connection with the prosecution of a crime.

That a state seeking to foster "legitimate family relationship" cannot do it by providing automatic inheritance by an illegitimate child of the estate of a mother who dies without a will out not of a father who dies intestate.

That the states must give way to the federal government in the regulation and enforcement of regulations intended to control industrial pollution of waterways.

That federal law bars a state from imposing hiring requirements that discriminate against women simply because they generally are shorter and lighter than man.

That a state cannot back out of a contract with a private party in order to protect against air pollution.

In criminal law, possibly the most important event was a non-actions the court refused 5 to 4 to use the senseless, brutal murder of a 10-year-old Iowa girl to overturn the so-called Miranda protections for criminal defendants. In a rare public display of temper, Burger, referring to Powell, said from the bench that the court someday might restore "rationality" with only one convent."

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Also part of the trend was the Dayton school decision. Nailing down a position staked out by both the Ford and Carter administrations. Rehnquist wrote that "only if there has been a systemwide impact may there be a systemwide remedy."

But Burger, in Detroit school case, emphasized that a remedy that cannot be excessive can be innovative. He endorsed measures to erase the stigmata - "habits of speech, conduct, and attitudes" - reflecting the "cultural isolation of children who have been educationally and culturally set apart from the larger community."

In the abortion ruling, from which dissenting Justices Blackmun. Brennan and Marshall predicted dire consequences, the court deferred to the political process in emphatic terms.The court held "merely" that neither the constitutional guarantee of equal protection of the laws nor the Social Security Act requires "a state tha telects to fund expenses incident to childbirth also to provide funding for elective abortions," Powell wrote for the majority.

"But we leave entirely free both the federal government and the states, through the normal processes of democracy, to provide the desired funding," he continued. "The issue present policy decisions of the widest concern. They should be resolved by representatives of this people, not by this court."

The court showed no such deference only 12 days earlier, on June 9, when with Powell in the majority, it ruled 6 to 3 that only direct purchasers, who almost always are middlemen rather than consumers, can sue price fixers for antitrust damages.

The court ruled 6 to 3 on Dec. 7 that employers could deny temporary disability to working women who become pregnant. Infuriated women's groups drew little comfort two weeks later when the court voted 7 to 2 to strike down, as sexually discriminatory, an Oklahoma law that let women buy "3.2 beer" at age 18, but made mom wait until they were 21.