Community organizer. Spellbinder. Gay-rights activist. Wendy to the lost boys of San Francisco. First openly homosexual candidate elected to office in California. Advocate for the elderly. Purveyor of pooper-scoopers.

During his cruelly abbreviated life, Harvey Milk - assassinated by his colleague Dan White 30 years ago tomorrow - was many things, none of them bashful.

Gus Van Sant's Milk, a biopic starring Sean Penn as the bottomless well of charisma himself, depicts the so-called Mayor of Castro Street as an accidental activist, electromagnetic force, and civil rights martyr.

For its mesmerizing first two-thirds, Van Sant keeps the film tightly focused on his subject, superbly played by Penn and intimately shot, home-movie style, by Harris Savides.

But when the director pulls back to detail Harvey Milk's fight against gay backlash, Milk gets derailed. And - dare I say it? - didactic.

Van Sant, maker of Good Will Hunting and Elephant, is most eloquent when he is least emphatic. He opens his film with '60s-era footage of police arresting gay men and cramming them into wagons like dogcatchers seizing rabid mutts. This climate of fear shaped the New York-born Milk, 40, who is introduced as he cheekily picks up a youth half his age (James Franco, terrific as Scotty Smith) on a subway platform.

Milk is a closeted suit who kicks the door down, emerging in tight jeans and love beads and encouraging others in the Castro, his adopted San Francisco neighborhood, to do the same. The difference between the subdued New York Harvey and his flamboyant San Francisco self-creation is that between Clark Kent and Superman.

As Penn incarnates him, Harvey is Supermagnet, a guy who attracts men who initially find him repulsive, charms straights who find his sexual preference offensive, and builds a coalition of gays, unionists and senior citizens to elect him district supervisor, as San Franciscans call their councilperson.

He was a skillful politician who impressed the opposition because he didn't ask for political or lifestyle endorsements; he asked for jobs. To many of his constituents Harvey may have been "different," but commonality was his political agenda. If it's true that students mimic their teachers, Harvey asks a state senator who would forbid gay teachers in the classrooms, then "why is it we don't have a hell of a lot more nuns?"

Typically wreathed in gloom, Penn plays Harvey Milk with radiant vitality and humor. (Has he laughed only in Sweet and Lowdown and Fast Times at Ridgemont High? If so, that's a shameful misuse of a natural resource.) His Harvey is so sunny that he naturally draws people to his warmth. So many, the film suggests, that Harvey's causes and campaigns drive a wedge between him and Scotty (another nuanced and transparent performance by Franco, so funny in Pineapple Express, so touching here).

More opaque is Josh Brolin as Harvey's political sparring partner Dan White, as awkward and inarticulate as Harvey is nimble and eloquent.

Milk's third act challenges its screenwriter (Dustin Lance Black) and audience alike. Harvey's final months were spent battling backlash, personified by singer and family-values spokeswoman Anita Bryant, who demonized homosexuals, seen in news clips that inadvertently elbow the movie's subject offstage.

Milk's final third is a rush of sequences, insufficiently dramatized. During Harvey's final year he finally wins public office, endures drama-queen love trouble (a miscast Diego Luna plays his temperamental lover Jack Lira), spars with fellow supervisor White, and successfully fights the proposition that would ban gay schoolteachers.

Instead of telescoping the events of Harvey's final year, Milk overmagnifies his fight against the likes of Bryant. As a consequence the film feels imbalanced.

For those interested in the subject, The Times of Harvey Milk (1984), Robert Epstein's Oscar-winning documentary, is required viewing.

Milk *** (out of four stars)

Directed by Gus Van Sant. With Sean Penn, James Franco, Josh Brolin, Emile Hirsch. Distributed by Focus Features.

Running time: 2 hour, 8 mins.

Parent's guide: R (sexual candor, brief violence)

Showing at: Ritz Five and Showcase at the Ritz/NJ


Contact movie critic Carrie Rickey at 215-854-5402 or crickey@phillynews.com. Read her blog, "Flickgrrl," at http://www.philly.com/philly/blogs/flickgrrl