Could an earlier ‘Milk’ release have killed Prop 8?

In Contention asks this question. I am skeptical, but definitely excited about the movie. They write:

A large portion of the film is dedicated to the fight against Proposition 6, a 1978 ballot measure that would have cost homosexuals working as educators their jobs. Their careers were at stake 30 years ago. Yesterday, it was their right to wed — and with wicked political conniving, the proponents of Prop 8 made this year’s fight about school in the end, just like Prop 6. “They’ll teach gay marriage in schools,” ignorant imbeciles would scream. “They’ll tell my son it’s okay for a man to marry a man.” Well, “they” would be right, but that’s beside the point.
. . .
Some of the film’s most inspiring and, indeed, captivating moments come during the sequence that details the Prop 6 fight. Consistently, Harvey Milk (Sean Penn’s career-best portrayal) makes the point, to paraphrase, “We have to make them understand that they know us.” That message, I think, might have carried a lot of heft if voters had made it to the polls four weeks later.