A federal judge in San Francisco has ruled that California's voter-backed initiative supporting traditional marriage is unconstitutional.

Chief U.S. District Judge Vaughn Walker ruled on Wednesday that Proposition 8 violates the Due Process clause of the Fourteenth Amendment as evidenced by the thin testimonies given by proponents of the measure.

"The minimal evidentiary presentation made by proponents does not meet the heavy burden of production necessary to show that Proposition 8 is narrowly tailored to a compelling government interest," Walker wrote. "Proposition 8 cannot, therefore, withstand strict scrutiny."

Walker also refuted Prop. 8 supporters' claims that allowing same-sex marriages would violate their first amendment rights to disagree with such a practice.

"Californians are prevented from distinguishing between same-sex partners and opposite-sex spouses in public accommodations, as California antidiscrimination law requires identical treatment for same-sex unions and opposite sex marriages," he wrote, adding that "moral views are an insufficient basis upon which to enact a legislative classification."

Furthermore, Walker said that the fact that Prop. 8 was passed by a majority of California voters – 52 percent in November 2008 - is "irrelevant, as 'fundamental rights may not be submitted to [a] vote; they depend on the outcome of no elections.'"

Walker's decision comes following a series of heated court debates earlier this summer, and while the ruling was expected, it has drawn strong reactions from advocates on both sides of the debate.

Tony Perkins of the Family Research Council called the ruling a "dangerous decision," likening it to the Roe v. Wade of same-sex marriage that could potentially overturn the marriage laws of 45 states.

"It's time for the far Left to stop insisting that judges redefine our most fundamental social institution and using liberal courts to obtain a political goal they cannot obtain at the ballot box," Perkins said.

"Marriage is recognized as a public institution, rather than a purely private one, because of its role in bringing together men and women for the reproduction of the human race and keeping them together to raise the children produced by their union," he added. "The fact that homosexuals prefer not to enter into marriages as historically defined does not give them a right to change the definition of what a 'marriage' is."

Jarrett Barrios, president of the Gay & Lesbian Alliance Against Defamation (GLAAD), meanwhile, said that the decision reflects a growing acceptance of same-sex couples in America.

"More and more Americans are supporting equality, and it is the stories of same-sex couples that are leading that charge across the nation," Barrios said. "Today's decision comes after same-sex couples from across California shared their personal stories with Judge Vaughn Walker and the public, helping to show that all loving and committed couples – straight and gay – should have the same opportunity to take care of and be responsible for each other."

Ramona Ripston, executive director of the ACLU of Southern California, said: "This decision affirms that in America, we don't treat people differently because of their sexual orientation. We rejoice at today's decision but there's a long road ahead toward establishing true marriage equality for same-sex couples."

Appeals on the ruling are expected to be filed, and many anticipate that the case will reach the Supreme Court.