The stacks of Supreme Court briefs filed on both sides of the same-sex marriage cases to be heard this month are roughly the same height. But they are nonetheless lopsided: There are no major law firms urging the justices to rule against gay marriage.

Leading law firms are willing to represent tobacco companies accused of lying about their deadly products, factories that spew pollution, and corporations said to be complicit in torture and murder abroad. But standing up for traditional marriage has turned out to be too much for the elite bar. The arguments have been left to members of lower-profile firms.

In dozens of interviews, lawyers and law professors said the imbalance in legal firepower in the same-sex marriage cases resulted from a conviction among many lawyers that opposition to such unions is bigotry akin to racism. But there were economic calculations, too. Law firms that defend traditional marriage may lose clients and find themselves at a disadvantage in hiring new lawyers.

“Firms are trying to recruit the best talent from the best law schools,” said Dale Carpenter, a law professor at the University of Minnesota, “and the overwhelming majority of them want to work in a community of respect and diversity.”

But some conservatives say lawyers and scholars who support religious liberty and oppose a constitutional right to same-sex marriage have been bullied into silence. “The level of sheer desire to crush dissent is pretty unprecedented,” said Michael W. McConnell, a former federal appeals court judge who teaches law at Stanford.

Representing unpopular clients has a long and proud tradition in American justice, one that experts in legal ethics say is central to the adversarial system. John Adams, the future president, agreed to represent British soldiers accused of murder in the 1770 Boston Massacre. Clarence Darrow defended two union activists who dynamited the Los Angeles Times building in 1910, killing 21 workers. Leading law firms today have lined up to defend detainees at Guantánamo Bay, Cuba, some accused of ties to Al Qaeda.

The Supreme Court has said criminal defendants are entitled to a lawyer. There is no right to counsel in civil cases, but most lawyers do not lightly turn away paying clients. Some lawyers, though, have been forced out of their firms for agreeing to take on clients opposed to same-sex marriage.

Whatever the reason, there is a yawning gap between the uniformity of views among legal elites and the more mixed opinions of the American public and the members of the Supreme Court. Polls indicate that while a slim majority of Americans support same-sex marriage, many remain skeptical, and the court’s decision, expected in June, is likely to be closely divided.

In earlier eras, the opposing sides were more evenly matched in landmark civil rights cases. One of the lawyers who argued in favor of segregated public schools in 1953 in Brown v. Board of Education was John W. Davis, a leader of the glittering New York law firm now known as Davis Polk & Wardwell. He was the Democratic nominee for president in 1924, the ambassador to Britain and the solicitor general, and he once held the record for most Supreme Court arguments in the 20th century.

Mr. Davis was “the most accomplished and admired appellate lawyer in America,” Richard Kluger wrote in “Simple Justice,” a history of the Brown case, which Mr. Davis lost in a unanimous 1954 ruling.

When the Supreme Court hears arguments on April 28 in the marriage cases, among them Obergefell v. Hodges, No. 14-556, the main lawyer opposing same-sex marriage will be John J. Bursch, who practices at a medium-size firm in Michigan. He served as the state’s solicitor general and has argued eight cases in the Supreme Court. But his firm, Warner Norcross & Judd, will not be standing behind him.

“When the State of Michigan asked me to handle the case, I asked the firm’s management committee about the engagement, and the management committee declined the representation,” Mr. Bursch said. “I am still a partner at Warner Norcross, but the firm has no involvement at all in the marriage case.”

Douglas E. Wagner, the firm’s managing partner, said the case was just too controversial. “This is an issue that engenders strong emotions on both sides for our clients, attorneys and staff,” he said.

Mr. Bursch’s experience was similar to that of Paul D. Clement, who served as solicitor general in the George W. Bush administration and has argued more than 75 cases in the Supreme Court. He defended a federal law, the Defense of Marriage Act, that denied benefits to married same-sex couples, losing in the Supreme Court in 2013 by a 5-to-4 vote. He is conspicuously absent this time around.

Mr. Clement seems to have learned a bitter lesson from the last case, United States v. Windsor. In 2011, as it was heating up, his law firm, King & Spalding, withdrew from the case under pressure from gay rights groups. Mr. Clement quit, moving to a smaller firm and continuing to represent his clients.

“I resign out of the firmly held belief,” he wrote at the time, “that a representation should not be abandoned because the client’s legal position is extremely unpopular in certain quarters.” Mr. Clement did not respond to a request for comment.

Ryan T. Anderson, a fellow at the Heritage Foundation who opposes same-sex marriage, said the episode was a turning point. “When the former solicitor general and superstar Supreme Court litigator is forced to resign from his partnership,” Mr. Anderson said, “that shows a lot.”

Gay rights advocates offer their own reason for why prominent lawyers are lined up on one side of the marriage cases. “It’s so clear that there are no good arguments against marriage equality,” said Evan Wolfson, the president of Freedom to Marry. “Lawyers can see the truth.”

The current attitude among elite lawyers about same-sex marriage grew very quickly, said Kenji Yoshino, a law professor at New York University.

“It usually takes much longer for a position to become so disreputable that no respectable lawyer will touch it,” said Professor Yoshino, a writer for The Ethicists column in The New York Times Magazine and the author of “Speak Now,” a history of the challenge to Proposition 8, California’s ban on same-sex marriage. (In 2013, the Supreme Court dismissed a case on Proposition 8, which had been overturned by a Federal District Court, without ruling on whether there was a constitutional right to same-sex marriage.)

Charles J. Cooper, who argued for Proposition 8, filed a supporting brief in the new cases. In 2009, he explained that he was able to handle the Proposition 8 case because he worked at a small firm. “The issue is too volatile, too controversial, too much of a tear in the fabric of the partnership” for a major law firm, he told The Legal Intelligencer. He declined a request for an interview.

The current climate, Professor McConnell of Stanford said, means that important distinctions are being lost. One is that it is possible to favor same-sex marriage as a policy matter without believing that the Constitution requires it.

But this is, he said, a topic he has learned to avoid. “You’re going to shut up, particularly if you don’t care that much,” he said. “I usually just keep it to myself.”

Check Also

Opposition Politician Ravi Philemon: MSM Screwed Up Reporting On M’sian Election!

"I expect better standards, especially from news outlets which are funded by taxpayers' monies."