Ruling against Proposition 8 could lead to federal precedent on gay marriage

California "has no interest in differentiating between same-sex and opposite-sex unions," U.S. District Chief Judge Vaughn R. Walker said in his 136-page ruling.

The ruling was the first in the country to strike down a marriage ban on federal constitutional grounds. Previous cases have cited state constitutions.

Lawyers on both sides expect the ruling to be appealed and ultimately reach the U.S. Supreme Court during the next few years.

It is unclear whether California will conduct any same-sex weddings during that time. Walker stayed his ruling at least until Friday, when he will hold another hearing.

In striking down Proposition 8, Walker said the ban violated the federal constitutional guarantees of equal protection and of due process.

Previous court decisions have established that the ability to marry is a fundamental right that cannot be denied to people without a compelling rationale, Walker said. Proposition 8 violated that right and discriminated on the basis of both sex and sexual orientation in violation of the equal protection clause, he ruled.