* -- Does Proposition 8 violate the separation of powers provisions of the constitution because it should have been approved by the Legislature first?

* -- If the Proposition 8 is constitutional, what is to become of the estimated 19,000 same-sex marriages performed between June 16 and the passage of the measure on Nov. 4?

As lawyer Shannon Minter began a presentation challenging the measure banning gay marriage approved by voters in November, justices raised the possibility that the effect of the initiative was narrow, changing only the terminology of "marriage" and not the rights of same-sex couples.

"Relegating same-sex couples to domestic partnership does not provide them with everything but a word," Minter replied. "Proposition 8 changes the basic nature of our government."

Minter argued that Proposition 8 was an improper revision because it changed the framework of the state constitution - the balance between minority and majority rights.

But he acknowledged that reducing rights of minority groups wasn't the issue considered in previous cases in which the court found improper revisions.

Lawyer Christopher Krueger, representing state Attorney General Jerry Brown, disagreed with gay marriage advocates that the measure was an improper revision of the constitution, saying it did not alter the fundamental structure of government.

Even though Krueger acknowledged he was advancing "somewhat of a novel theory," he nonetheless argued that Proposition 8 was unconstitutional. He said it conflicted with an "inalienable right" to liberty that the state Supreme Court found last year included the right of same-sex couples to marry.

But opponents of gay marriage, represented by lawyer Kenneth Starr, said the other side had failed to recognize the "inalienable right" of the people to change the constitution. He noted that California voters through the initiative process voted to restore the death penalty, which the state Supreme Court had previously found to be "cruel and unusual" punishment.

"The people do have the raw power to define the rights," Starr said. "We govern ourselves - and we may govern ourselves unwisely."

The court's May 16 decision stemmed from legal challenges to Proposition 22, another measure passed by voters in 2000 that banned gay marriage.

"The court is in an awkward position," said Vikram Amar, a University of California, Davis law professor.

The justices are being asked to oversee the process of checks and balances on the courts, he said, "and that is a hard thing for a court to do. ... This has the potential to be a blockbuster decision if they decide to invalidate Proposition 8."

Such a ruling could raise questions about the initiative process, or the future ability of a majority of voters alone to change the constitution at the ballot box, especially when an initiative abridges the rights of a group.

Beyond that is the historic and broad social impact of a decision.

The justices split 4-3 on the last gay marriage decision, background that lends intrigue to the hearing and speculation over questions justices might pose during the attorneys' oral arguments. Kennard, for example, was part of the majority in favor of same same-sex marriage, but she dissented from the majority that voted to review challenges to Proposition 8.

Dozens of legal briefs have been submitted to the court by groups on both sides of the debate.

END