When Sean Penn won the Best Actor Oscar for his portrayal of slain San Francisco Supervisor Harvey Milk two weeks ago, he used his acceptance speech to rail against supporters of California's Proposition 8, which last November repealed a State Supreme Court ruling extending marriage rights to same-sex couples.

Penn's confrontational tone was in keeping with his prickly public persona, but it was also in line with his character's real-life activism. Milk was one of the first openly gay elected officials in the United States, and the fact that he was openly gay defined his policies and goals.

"Milk," the movie for which Penn won the Oscar, works better as political history than it does as biography. Harvey Milk's long-term goal was to help build a society in which homosexuals participated fully without having to hide or deny their sexual preferences. But because he understood that many people abhorred those sexual preferences, he knew such a society could not be built on persuasion. He would have to force the issue through political action, just as the civil-rights movement won equality for blacks.