Brown v. Board of Education, meet Perry v. Schwarzenegger. The legal showdown has begun in San Francisco, where two same-sex couples have challenged Proposition 8, a voter-approved law that outlawed gay marriage in the state of California in 2008, saying it violates the U.S. Constitution. Advocates on both sides of the battle believe it could be history in the making.

The case, which began Monday, is the first challenge of a state ban on same-sex marriage to be heard in a federal court. If it makes its way to the U.S. Supreme Court, as expected, it could ultimately determine whether gay marriage in the United States receives constitutional protection.

The details of the case are almost as dramatic as the potential consequences.

Two of its lead attorneys faced off in the epic legal contest that decided the 2000 presidential election, with David Boies representing Al Gore and Theodore Olson acting on behalf of George W. Bush. They are now working together to uphold the right of gays to marry, even though Mr. Olson is one of the country’s most conservative lawyers.

Read the rest of Siri Agrell’s article in The Globe and Mail here.