Posted on Thu, Feb. 20, 2003 Acting outHollywood antiwar sentiment is loud and clear. And so is the opposition.By Beth GillinInquirer Staff Writer AP photo Martin Sheen and James Cromwell turned out for Saturday's protest on Hollywood Boulevard in Los Angeles. Celebrities do affect public opinion, media experts say. It's the largest outpouring of star-powered anti-war sentiment since the Vietnam War.Barbra Streisand, Martin Sheen, Jessica Lange, Spike Lee, Susan Sarandon, Tim Robbins, Martin Scorsese, Sean Penn, Robert Redford, Dustin Hoffman, Ossie Davis, Robert Altman.Some of the country's biggest stars are loudly against invading Iraq.Edward Norton, Tyne Daly, Danny Glover,...