In a 136-page ruling, U.S. District Judge Vaughn Walker ruled Wednesday that Proposition 8, California's voter-approved same-sex marriage ban, violates the U.S. Constitution. 

His decision was highly critical of the measure. "Proposition 8 singles out gays and lesbians and legitimates their unequal treatment," he wrote. "Proposition 8 perpetuates the stereotype that gays and lesbians are incapable of forming long-term loving relationships and that gays and lesbians are not good parents."

Walker brushed aside one of the common arguments in favor of the proposition. "That the majority of California voters supported Proposition 8 is irrelevant, as 'fundamental rights may not be submitted to [a] vote; they depend on the outcome of no elections.'"

The judge wrote that sexual orientation is an innate characteristic that can't be chosen or changed. "No credible evidence supports a finding that an individual may, through conscious decision, therapeutic intervention or any other method, change his or her sexual orientation," he wrote.

Walker also drew parallels to freed slaves' marriage rights: "Because slaves were considered property of others at the time, they lacked the legal capacity to consent and were thus unable to marry. After emancipation, former slaves viewed their ability to marry as one of the most important new rights they had gained."

And he asserted that domestic partnerships can never be equal to marriage. "Domestic partnerships lack the social meaning associated with marriage, and marriage is widely regarded as the definitive expression of love and commitment in the United States."

You can read the full decision here.

Click here for complete Prop. 8 coverage, including a map of planned events, videos and a profile of Judge Walker.