The opinion by Chief Justice John G. Roberts Jr. was unanimous.
It was a setback, although hardly an unexpected one, to a coalition of law schools that brought the constitutional challenge, as well as to the Association of American Law Schools, which represents nearly all accredited law schools and since 1991 has required adherence to a nondiscrimination policy on sexual orientation as a condition of membership.
Many law schools initially chose to comply with the association's policy by barring military recruiters or by taking such steps as refusing to help the recruiters schedule appointments or relegating them to less favorable locations for meeting with students.
Congress responded with a series of increasingly punitive measures, all known as the Solomon Amendment, culminating in the 2004 statute at issue in the case. It requires access for military recruiters "that is at least equal in quality and scope" to access for other employers, on pain of forfeiting grants to the entire university from eight federal agencies, including the Departments of Defense, Education, and Health and Human Services.
With hundreds of millions of dollars at stake, all but a handful of law schools yielded. Nearly three dozen banded together as the Forum for Academic and Institutional Rights and turned to the courts.
Carl C. Monk, executive director of the law school association, said in an interview on Monday that the group would continue to require its member schools to engage in "significant" activities to counter the impact of the Solomon Amendment, such as organizing faculty forums at which the military's policy could be analyzed and challenged.
The plaintiffs had persuaded the federal appeals court in Philadelphia that the Solomon Amendment imposed an "unconstitutional condition" on the universities' receipt of federal money by requiring them to surrender their First Amendment rights and become involuntary carriers of the government's anti-gay message.
But Chief Justice Roberts said on Monday that the plaintiffs' theory of the case, as well as the opinion by the United States Court of Appeals for the Third Circuit, was based on a fundamental misperception about what the Solomon Amendment was imposing.
"As a general matter, the Solomon Amendment regulates conduct, not speech," the chief justice said. "It affects what law schools must do — afford equal access to military recruiters — not what they may or may not say."
Pointing out that law schools remained free to disavow the military's policy, to denounce it or even to help students organize protests, Chief Justice Roberts said that "the Solomon Amendment neither limits what law schools may say nor requires them to say anything."
Citing a 1990 Supreme Court decision that upheld an equal-access requirement for student religious clubs in high schools, he continued: "We have held that high school students can appreciate the difference between speech a school sponsors and speech the school permits because legally required to do so. Surely students have not lost that ability by the time they get to law school."
To the extent that speech is involved when a military recruiter visits a campus, the chief justice said, the speech is "clearly" the government's, not the law school's. He said that placing the incidental assistance that universities must provide to military recruiters on the same plane as compelling students to recite the Pledge of Allegiance "trivializes the freedom protected" by a 1943 Supreme Court decision holding that the Pledge may not be required.
While the conclusion that the Solomon Amendment does not directly infringe on the law schools' free-speech rights was at the heart of the court's analysis, the opinion contained several other important threads.
One was the conclusion that allowing military recruiters on campus was not an "inherently expressive" activity. Therefore, Chief Justice Roberts said, the case was not governed by two Supreme Court precedents dealing with freedom of expression. One of them declared unconstitutional a Florida law that required newspapers to grant a "right of reply." The other allowed organizers of the St. Patrick's Day parade in Boston to exclude a gay-pride group despite a nondiscrimination ordinance.
The difference, the chief justice said, was that both the newspaper and the parade organizers were engaged in expression with which the government could not constitutionally interfere, while law schools "are not speaking when they host interviews and recruiting receptions."
Another conclusion was that the Solomon Amendment did not interfere with another interest protected by the First Amendment, the law schools' freedom of association. The appeals court had found a violation of this freedom by analogy to a Supreme Court decision in 2000 that gave the Boy Scouts the right to exclude a gay scoutmaster despite a New Jersey nondiscrimination law.
The analogy was incorrect, Chief Justice Roberts said. Unlike Boy Scout leaders who become part of the organization, "recruiters are, by definition, outsiders who come onto campus for the limited purpose of trying to hire students — not to become members of the school's expressive association," he said, adding, "This distinction is critical."
The court also rejected an alternative theory of the case put forward by groups of professors from Harvard and Columbia Law Schools. Under their theory, the Solomon Amendment's mandate for equal access could be met by a school that simply excluded all employers who did not attest to a nondiscrimination policy. "That is rather clearly not what Congress had in mind," Chief Justice Roberts said, adding that this interpretation of the Solomon Amendment "would render it a largely meaningless exercise."
The constitutional power of Congress to "raise and support armies" was another significant thread in the opinion. Chief Justice Roberts said that in exercising that power, Congress could have directly required universities to admit military recruiters, instead of taking the more indirect approach of making access a condition of federal financing. "It is clear that a funding condition cannot be unconstitutional if it could be constitutionally imposed directly," he said.
The military interviews about 2,500 law students each year and hires about 400 for its Judge Advocate General's Corps, said Ellen Krenke, a spokeswoman for the Defense Department. The court's decision will not change the actual practice on most campuses because all but a few are in compliance with the amendment, she said.
The decision, Rumsfeld v. Forum for Academic and Institutional Rights, No. 04-1152, was announced on a day when, coincidentally, some four dozen uniformed Army lawyers were in the courtroom to be sworn in as members of the Supreme Court bar.
Paula C. Johnson, a named plaintiff in the lawsuit who is a law professor at Syracuse University and a visiting professor this semester at the City University of New York's law school, said that it was too early to talk about what campuses might do, but that she expected "things will begin to happen" as opponents of the military's policy had time to better organize.
"This could be a very important galvanizing measure," she said.
Mr. Monk, of the law school association, said in the interview that law schools retained the obligation to "create a welcoming environment for all their students." He added, "Ultimately, our hope is that gay and lesbian students who want to serve their country by becoming military attorneys will be able to do so."