Director Gus Van Sant has had a very successful 2008. This spring he released iParanoid Park/i, a haunting indie feature starring a mostly unknown cast about a young skateboarder who gets involved with the wrong people and unwittingly becomes an accomplice to murder.

Van Sant did a masterful job with iParanoid Park/i, and following its release he could have put his feet up and been satisfied with the year’s work. Instead he made iMilk/i, and it’s his most impressive, accomplished movie-mainstream or independent-to date. The film, written by Dustin Lance Black (a main writer for HBO’s iBig Love/i), tells the story of America’s first openly gay elected official, Harvey Milk, who served on the San Francisco Board of Supervisors. The screenplay details his rise to power in the late 1970s, as well as his tragic, sudden assassination in 1978.

iMilk/i couldn’t have arrived at a better time, hot off the heels of Barack Obama’s victory and the disputable passage of Proposition 8. With the political landscape of our country rapidly changing, this is the moment for voices of change to speak out, and the film’s sense of urgency and purpose is palpable. Sean Penn shines in the title role, giving one of the best performances of his career. Joining him is a stellar ensemble, including James Franco, Emile Hirsch, Josh Brolin, Diego Luna, Alison Pill and Victor Garber.

Unlike many other well-made biographical films that wind up feeling like inconsequential glances to the past (iThe Aviator/i, iA Beautiful Mind/i), iMilk/i is utterly alive and vibrant with purpose.

The film begins with 40-year-old Harvey Milk’s 1970 move from New York City to San Francisco, after falling in love with the young Scott Smith (James Franco). Realizing that his neighborhood, along with the rest of the nation, is seriously homophobic, he decides to make something of his uneventful life and campaign for a spot on the city’s Board of Supervisors. Running and losing many times doesn’t dampen Harvey’s spirit, and he is relentless in the pursuit of his goal until he finally reaches it.

Coincidentally paralleling the controversial Proposition 8 is the film’s focus on 1977’s Proposition 6. Its aim to ban homosexuals from teaching in public schools infuriates Milk and much of the nation. It is Milk’s passionate fight against Proposition 6 that allows Van Sant to show this man as a pioneer, one who is worth remembering in this day and age.

He tells this story with the same spirit of constant progress that Milk himself had, never lingering too long on any moment but still allowing the viewer to absorb its power.

Sean Penn envelops himself in the man, completely embodying his future-forward attitude and inspiring sense of hope. It’s one of the first performances from Penn in years that doesn’t seem like a showcase, e.g. iI Am Sam/i and iAll the King’s Men/i. He never once sacrifices truth for an opportunity to strut his stuff as an actor. He lives in Harvey, radiating his warm humor and soulful passion.

Dustin Lance Black’s triumphant script focuses on the aspects of its subject that Milk himself took most seriously. His relationships take a backseat to his dreams, and he elegantly accepts his personal failures as necessary for the greater good.

Lance Black never uses melodrama to show us this, instead leaving many of these insights up to the actors and the audience. He devotes the majority of the film to Milk’s work as a gay rights activist, as someone who fought fearlessly for what he believed in. It’s clear that Lance Black wrote this not because he simply found the man interesting, but because there is still work to be done today that Harvey Milk would be doing if he were alive.

iMilki/ has the same conviction that iAn Inconvenient Truth/i had, which is one that aims to move its audience toward action. Van Sant resurrects Harvey Milk to finish the job he set out to do in the 1970s.

He is simply not content with his film joining Hollywood’s massive archives; he is trying to make a difference.