They have lobbied in the halls of Congress wearing pig costumes and wandered the streets of Manhattan dressed in evening wear and rags. But the three founders of the women's antiwar group Codepink are seasoned advocates who may have pulled off the protest coup of the convention: While thousands of demonstrators chanted on the streets, drawing only glancing attention from the Republicans, their members were inside Madison Square Garden night after night, unfurling banners and baring slogans, forcing even the president to take notice. ''We don't want just to be outside on the street talking to ourselves,'' said Medea Benjamin,...