“We conclude this trial, your honor, where we began,” Ted Olson, who is representing two gay couples in the first federal trial to consider the constitutionality of a gay marriage ban, began. “This case is about marriage and equality,” he continued. “The fundamental constitutional right to marry has been taken away from the plaintiffs and tens of thousands of similarly situated Californians.”

Chief U.S. District Judge Vaughn Walker heard final arguments Wednesday in a San Francisco courtroom. Proposition 8's November 2008 approval struck a severe blow to the gay marriage movement, denying gay couples in the country's most populous state the right to marry just months after the state's highest court had legalized the institution.

About 18,000 gay and lesbian couples married before voters narrowly reversed the ruling.

The trial concluded after two-and-a-half week's worth of testimony in January, but Walker said he wanted to review the evidence before listening to closing arguments.

Olson went first. He played video clips from the trial where the four plaintiffs – a gay couple and a lesbian couple denied the right to marry because of Proposition 8 – were asked why they wish to marry.

Jeffrey Zarrillo, 36, testified about his partner, Paul Katami, 37, saying he is “The love of my life. I love him more than I love myself. … And I want nothing more than to marry.”

“I would feel more secure. I would feel more accepted. I would feel more pride. I would feel less like I had to protect my kids,” Sandra Stiers, 47, said about the opportunity to marry her partner Chris Perry.

Olson rejected ban backers' arguments that gay marriage harms society and insisted that proponents sponsored Prop 8 out of animus towards gay people.

Representing ProtectMarriage.com, the primary sponsor of Proposition 8, Charles Cooper argued that limiting marriage to heterosexual unions was not based on bigotry or animus towards gay couples, but was required to maintain an orderly society.

“The marital relationship is fundamental to the existence and survival of the race,” he said. The purpose of marriage, Cooper said, “is to provide society's approval to that sexual relationship and to the actual production of children.”

Walker, however, appeared skeptical. He noted that procreation is not a requirement to marry, and suggested that marriage was more about building a future or sharing in life than procreating.

“Marriage is a right which extends fundamentally to all persons, whether they're capable of producing children, incarcerated or behind in their child-support payments,” he said.

Cooper disagreed, saying that marriage was designed to discourage “irresponsible procreation,” which does not apply to gay couples. Gay and lesbian couples, he said, would only participate in responsible procreation because they would require a third party.

Walker is expected to hand down a ruling in July. He could decide to overturn the gay marriage ban and allow gay couples to begin marrying in California immediately. Whatever the outcome, the ruling is certain to be appealed to the Ninth U.S. Circuit Court of Appeals and possibly the Supreme Court.