California's Supreme Court agreed Wednesday to review three lawsuits that seek to invalidate Proposition 8 – the constitutional amendment that forbids gay marriage in the state – but denied a stay of the measure that would have allowed gay couples to continue marrying in the state.

The court also indicated it would decide the fate of 18,000 gay marriages that took place between June, when a California Supreme Court decision that overruled a 2000 voter-approved marriage ban took effect, and November, when voters agreed to ban gay marriage again.

In a closed session meeting in San Francisco, California's highest court agreed to review the gay marriage ban, but said it would not postpone its start.  The court scheduled a hearing in March.

Proponents of the gay marriage ban have already threatened to work to oust any justice who votes to invalidate Proposition 8. And they have already begun targeting politicians who support gay marriage, Senator Dianne Feinstein and Governor Arnold Schwarzenegger included.

Tony Perkins of the Family Research Council said last week that the governor was advocating “anarchy” because he supported efforts to invalidate the constitutional amendment. Forty-four Democratic legislators have signed a friend of the court brief in support of the challenge.

Pro-gay rights activists announced they would challenge the constitutional amendment the day after Election Day, saying the measure was invalid because it altered the Constitution itself, instead of merely amending it.

Proposition 8 alters the Constitution's “core commitment to equality for everyone by eliminating a fundamental right from just one group, lesbian and gay Californians,” the pro-gay rights groups argue.

“If the voters approved an initiative that took the right to free speech away from women, but not from men, everyone would agree that such a measure conflicts with the basic ideals of equality enshrined in our Constitution,” Jenny Pizer, a staff attorney with Lambda Legal, said in a statement announcing the challenge.

Removing fundamental rights guaranteed by the Constitution is a revision, not an amendment, supporters of gay marriage say. Revising the state Constitution in California requires a constitutional convention or legislative approval before being sent to voters for approval.

“A major purpose of the Constitution is to protect minorities from majorities,” said Elizabeth Gill, a staff attorney with the ACLU of Northern California. “Because changing that principle is a fundamental change to the organizing principles of the Constitution itself, only the legislature can initiate such revisions to the Constitution.”

A decision for review of the lawsuits is not an endorsement of gay marriage. In fact, most scholars agree the challenge is a longshot.

“It's very hard to argue that this narrowly written Constitutional amendment changes the fundamentals of our state government,” Ethan Leib, a Constitutional law professor at UC Hastings in San Francisco, told

Leib, who is a supporter of gay marriage, called California's Constitutional amendment procedure “flexible and inviting,” because “the people, rather than the judges, get to say what the Constitution means.”