WASHINGTON — A high school principal was acting reasonably and in accord with the school’s anti-drug mission when she suspended a student for displaying a “Bong Hits 4 Jesus” banner, her lawyer told the Supreme Court yesterday.

“The message here is, in fact, critical,” the lawyer, former independent counsel Kenneth Starr, said during a lively argument about whether the principal violated the constitutional rights of the student.

On the other side, attorney Douglas Mertz of Juneau, Alaska, urged the justices to see the case as being about free speech, not drugs.

The dispute between Joseph Frederick, who in 2002 was a high school senior, and principal Deborah Morse has become an important test of the limits on the free-speech rights of students.

Justice Breyer, addressing Mr. Mertz, said he is struggling with the case because a ruling in Mr. Frederick’s favor could encourage students to go to absurd lengths to test those limits.

A ruling for Ms. Morse, however, “may really limit free speech,” Justice Breyer said.

The Bush administration, backing Ms. Morse, wants the court to adopt a broad rule that could essentially give public schools the right to clamp down on any speech with which it disagrees.

Scores of students waited outside the court early yesterday for a chance to listen to the arguments.

“I would never do it, but at the same time, it’s free speech,” said Chaim Frenkel, 17, of Silver Spring, Md. Mr. Frenkel was one of 13 seniors and their teacher from the Melvin J. Berman Hebrew Academy who arrived at the court at 4:30 a.m.

Natasha Braithwaite, 20, a junior at Columbia Union College in Takoma Park, Md., got in line at 7 a.m. with a definite opinion about the case. “In every possible way, his First Amendment rights were violated,” Ms. Braithwaite said.

Mr. Frederick was a high school senior in Juneau when he decided to display the banner at a school-sanctioned event to watch the Olympic torch pass through the city on its way to the 2002 Winter Games in Salt Lake City.

Ms. Morse believed his “Bong Hits 4 Jesus” banner was a pro-drug message that schools should not tolerate. She suspended Mr. Frederick for 10 days. Mr. Frederick sued Ms. Morse, and that case now is before the court.

Mr. Frederick acknowledged he was trying to provoke a reaction from school administrators with whom he had feuded, but he denied that he was speaking out in favor of drugs or anything other than free speech. A bong is a water pipe that is used to smoke marijuana.

“I waited until the perfect moment to unveil it, as the TV cameras [following the torch relay] passed,” Mr. Frederick said.

Ms. Morse and the Juneau school district argue that schools will be powerless to discipline students who promote illegal drugs if the court sides with Mr. Frederick. The Bush administration, other school boards, and anti-drug school groups are supporting Ms. Morse.

Mr. Frederick, now 23, counters that students could be silenced if the court reverses the appellate ruling. A wide assortment of conservative and liberal advocacy groups are behind Mr. Frederick.