An 11-judge appeals court panel heard arguments Tuesday on whether a...gender-discrimination lawsuit against...Wal-Mart can proceed as the largest class-action lawsuit in history... [Wal-Mart's attorney] Theodore Boutrous...argued that...a suit so massive...can't be tried as a class action without trampling the company's right to defend itself... But attorney Brad Seligman..., representing the plaintiffs, said there's nothing wrong with letting his clients prove the company "approved of and acquiesced for years" to a pattern and practice of its regional management allowing gender discrimination in pay and promotions... The Obama administration has sided with the plaintiffs: The U.S. Equal Employment Opportunity Commission filed a brief last week arguing Wal-Mart's position would keep the government from ever seeking punitive damages from companies with a pattern of discrimination and would impede the EEOC's ability to enforce discrimination laws.