The trial to decide whether states can outlaw same-sex marriage started with testimony from two gay couples.
"We are all Americans who simply want to get married just like everyone else," plaintiff Jeff Zarrillo said. "We believe in our Constitution and that the courts will lead the way to equality like they have done so many times in the past."
Attorneys for Proposition 8-- the measure that upheld traditional marriage in California-- are focusing on democratic rights.
"Clearly the big issue on this case is going to be the role of the courts and the rights of the people ultimately to make decisions in the democratic process and to be able to have their votes counted," explained attorney Andre Pugno.
While the Prop 8 trial is underway, pastors from across the country have been meeting with traditional marriage supporters in Washington, D.C. Click play for more on the National Marriage Summit with Bishop Harry Jackson, following Heather Sells' report.
California voters approved Prop 8 at the ballot box in Nov. 2008, but attorney Ted Olson argued that anti-gay bias was at work.
CBN News spoke with Jordan Lorence, an attorney defending Prop 8.
"One of the main themes Olson made is how the Prop 8 committee appealed to the prejudice of people and tried to motivate them to vote for Prop 8 because of hatred against homosexuals," he said.
Yet, Prop 8 attorneys say they're concerned about hatred against traditional marriage supporters.
During the campaign against gay marriage, church vandalism was witnessed and some Prop 8 supporters received death threats, including Pastor Jim Franklin in Fresno, Calif.
"I've had threats before and you don't know how seriously to take them," Franklin recalled. "The chief of police called me back in about two minutes and said 'Yes, we're taking it very seriously because of the nature of it.'"
That kind of intimidation is why Prop 8 supporters oppose broadcasting the trial and posting it on YouTube. They fear for the safety of witnesses.
Opponents, however, say Amerricans should be able to view the debate for themselves.
The U.S. Supreme Court will make a final decision on the issue Wednesday.
Meanwhile, the California trial against Prop 8 is expected to last two to three weeks. No matter the outcome, the case is expected to be appealed to the high court.