Atlanta-based law firm King & Spalding won plaudits Monday from gay activists for backing out of an agreement to argue to uphold the federal ban on gay marriage. But a day later the reviews were a bit more bruising in the legal community.

Top lawyers and law professors, with some notable exceptions, called it an embarrassing blunder by the prestigious firm or a betrayal of a client and legal principles. Others think King & Spalding, whose clients include General Electric and Coca-Cola, may have backed out because the firm fears the fallout from leading an anti-gay legal fight.

King & Spalding's announcement it would not represent congressional House Republicans in their quest to defend court challenges to the federal Defense of Marriage Act (DOMA) and the subsequent decision of Paul Clement, the lawyer in the case, to quit the firm and take it elsewhere was the talk Tuesday among Yale University Law School faculty, said Lawrence Fox, a Yale professor and expert in legal ethics. DOMA defines marriage "for federal tax, Social Security and other purposes" as only a union between a man and a woman.

“We really go down a bad road if we say law firms can't take on (controversial) matters or people will assume you have those views," said Fox. "I’m going to walk into my class today and I’m going to use this. I’m tearing up my lesson plan ... to talk about this case."

Fox said the law firm's withdrawal didn't raise any legal ethical issues because the case stayed with Clement, whom he said was one of the nation's top appellate lawyers. Clement is taking a position at the boutique Washington law firm Bancroft PLLC  to continue representation.

But David Zarfes, an associate dean at the University of Chicago law school, said the King & Spalding set an unsettling precedent.

"It looks like(King & Spalding is) caving in to political pressure and I think everybody has the right to get the best legal representation they can," said Zarfes, an ethics expert. "This may have a chilling effect on law firms. That is not a good thing."

Atlanta lawyer Emmet Bondurant a champion against the death penalty and other causes, applauded King & Spalding's decision. He said because the firm's management hadn't vetted the case well enough with its staff  -- King & Spalding's official reason for walking away from the case -- it would have been unfair to those attorneys who opposed involvement on philosophical grounds.

Randy New, who practices employment discrimination law, said he was surprised a firm that had portrayed itself as sympathetic to gay causes would be defending DOMA.

"What was jarring about King & Spalding's decision -- and it was jarring -- is ... this was a law firm that appeared to be pro-gay and it took a case on the opposite side,” said New, a member of the local gay Stonewall Bar Association. “I think they understood the case was going to be explosive but my guess is they didn’t think about all the people who they cared about and what their reaction was going to be -- people at the law firm, their clients and the gay community.”

Jessica Gabel, a Georgia State University law professor, said it isn't uncommon for law firms to represent clients with whom some of its lawyers might have strong disagreements with politically, and King & Spalding has had controversial clients. The law firm, for example, won praise for is representation of condemned men on death row and was one of the primary firms that represented tobacco companies.

Gabel and Bondurant said the firm's agreement that none of its staff would lobby against congressional Republican's position or take public positions against it was unfair to gay employees -- even though normally staff members would be prohibited from acting against a client's interest.

“This is different and it is different because it affects personal relationships,” Bondurant said. “This is not an ordinary client. “The client is a bunch of elected politicians in Congress who want to advocate a philosophical and political position that is not widely shared."

King & Spalding, which has more than 800 lawyers worldwide and represents half of the Fortune 100 companies, according to one survey, had agreed to take the case for $520 an hour, paid with taxpayer funds appropriated from their congressional budget. House Republicans hired Clement and King & Spalding to continue the appeal of a decision by a federal judge in Massachusetts, who struck down the act last summer.

New said King & Spalding may have balked in part because it realized some of its corporate clients would not want it to be so publicly associated with an anti-gay issue. George Cohen, an expert of professional responsibility for lawyers and corporate law, agreed but said the controversy could cut both ways.

“It doesn’t look great if a firm develops a reputation that if there is a political controversy that we are just going to fold," said Cohen, a law professor at the University of Virginia.

“In some sense, they could be making a business decision as much as a principled decision. If it was a principle thing they would have declined to represent the client in the first place.

Staff writers Bill Rankin and Jim Galloway contributed to this story