Five is the magic number, as they say at the Supreme Court. And the justices have just entered the nerve-racking, nail-biting season of "holding five," that is, trying to keep a majority of the justices on a single opinion in the knottiest cases.

Chief Justice William H. Rehnquist has written how one of his predecessors, Charles Evans Hughes, admitted that despite his efforts to draft clear opinions, when he needed a fifth colleague who insisted on putting in a paragraph that did not "belong," in it went, and "let the law reviews figure out what it meant."

"I still have nightmares," says Georgetown University law professor Julie O'Sullivan, a former law clerk to Justice Sandra Day O'Connor, who remembers the end-of-term anxieties over whether majorities would hold.

"You've been working on opinions since October," explains Paul Clement, a former clerk to Antonin Scalia. "By June, all the easy cases have been decided and only the tough ones are left. You work late into the night. You end up having ridiculous conversations at 2 in the morning."

Ten years ago around this time, chaos broke out behind the velvet curtains as Justice Anthony M. Kennedy switched off of what was then the majority opinion by Justice William J. Brennan Jr. in a big race discrimination case. The case had been through two sets of oral arguments and was awaiting a decision for seven months.

"Tony's dissent leaves me without a Court," Brennan wrote to his colleagues in Patterson v. McLean Credit Union. Soon after, Rehnquist assigned the majority opinion to Kennedy, and eventually set a date that would let the court finally "bring down this case."

The last-minute turn led Justice John Paul Stevens to observe that since the justices first staked out their positions, "at least three members of the present majority [have] modif[ied] their views--and, in one case, his vote." The whimsical, bow-tied Stevens added, "I have no quarrel with this process . . . having done so a number of times myself."

But it is a "process" that happens more in June and brings foreboding to the marble halls. Only when the remaining opinions are announced this term--25 cases are left; 51 have been handed down--will the public get a glimpse of some of the difficulty in deciding the cases.

Sometimes the divisions are evident by the lack of five votes on key parts, particularly the rationale, of a ruling. Individual justices explain their legal reasoning--and individual each one is: Nothing garners a majority. Sometimes a dissent reads as if it was once a majority opinion.

Among the biggies the justices are still grappling with this term are a dispute over the constitutionality of a Chicago ordinance targeting gang loitering, four cases on the breadth of federal disabilities law and three cases that will determine the boundary between federal and state power.

"This is when nerves start to fray," said Peter Rubin, former clerk to Justice David H. Souter, of the short tempers and long nights. "The harder cases take longer. The emotional stakes for justices writing are greater. The few really personal attacks that justices have made toward each other have come at the end of the term."

It was on the last day of the 1988-89 term when Scalia let loose his memorable vitriol on O'Connor, saying her position in an abortion case "cannot be taken seriously." An opponent of abortion rights, Scalia called O'Connor's refusal at that time to even consider whether Roe v. Wade should be overturned "the least responsible" course, worse in his mind than even deciding to reaffirm it.

But there are other ways to blow off steam.

"Even at the worst times," said Clement, "you could go shoot hoops in the middle of the night," in the upstairs gymnasium. Situated above the courtroom, the gym is aptly known as "the highest court in the land."

THIS MONTH IN COURT HISTORY: Ten years ago in June, the court said state laws against flag desecration violate the First Amendment in Texas v. Johnson. Twenty years ago, the court ruled that a federal law forbidding race discrimination on the job (Title VII) does not bar employers from using race-based affirmative action in United Steelworkers of America v. Weber. And 30 years ago, the court said the House of Representatives acted unconstitutionally when it voted to exclude Rep. Adam Clayton Powell (D-N.Y.) for misconduct in Powell v. McCormack.

Full Court Press runs the first Monday of the month. Joan Biskupic's e-mail address is