The Monster star has teamed up with organizers of the Courage Campaign to draw the crowds at the forthcoming Meet in the Middle for Equality rally in Fresno, a city between Los Angeles and San Francisco, reports Eonline.com.
She says, "We know the people whose lives are on the line -- those who identify as gay, lesbian, bisexual, or transgender -- will be there. But we need everyone there. Especially straight people."
The California Supreme Court will decide on lawsuits filed against Prop 8, the ballot proposition outlawing same-sex marriage, in the coming weeks.
But Theron and activists at the Courage Campaign are planning the rally for the weekend after the ruling is announced -- regardless of the court's decision.
Explaining the date and choice of location, she adds, "While we don't know when the Supreme Court will rule exactly, we know it will be within the next four weeks. Californians need to be prepared to commit right now to go to Fresno on the Saturday after the decision is announced, no matter what that decision may be.
"The battle for equality has to be fought in Middle America -- in places like Fresno, California -- not just in gay-friendly cities like San Francisco and Los Angeles. California's Central Valley population is far more reflective of national attitudes towards LGBT (lesbian, gay, bisexual and transgender) equality -- and until we engage the communities of Middle America, we will not achieve full equality in California."
South African-born Theron has previously compared America's rules on same-sex marriages to her native country's past apartheid laws.
She said, "I don't like living in an elitist world. It bothers me. I don't want to be part of an elitist sexual preference. It bothers me. Maybe it's because I come from a country where I lived under apartheid, but this is a form of apartheid and I don't want to be a part of that."
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