On November 5, 2008, the day after Proposition 8 was approved by voters, the California ACLU affiliates joined with the National Center for Lesbian Rights, Lambda Legal Defense and Education Fund, Inc., and the law offices of David C. Codell, Munger, Tolles & Olson, and Orrick Herrington & Sutcliffe to file suit in the California Supreme Court to invalidate Proposition 8.

We argue that Proposition 8 is a revision to the California Constitution, rather than an amendment, and therefore cannot be adopted by a simple majority vote on an initiative. Revisions, unlike amendments, must be approved by a two-thirds vote of the legislature before being submitted to the voters or a constitutional convention. Our position is that Proposition 8 is a revision because it subverts the constitutional guarantee of equal protection, allowing a simple majority of voters to deprive a particularly vulnerable minority, such as LGBT people, of fundamental rights, and prevents courts from exercising their unique responsibility to uphold the equal protection rights of minorities.

Our case, Strauss et al. v. Horton et al., was consolidated with cases filed by other plaintiffs, including various individuals and a coalition of cities and counties. The California Supreme Court agreed to decide the case in the first instance, without waiting for lower courts to address the issue. The court placed similar cases, filed by other plaintiffs including various civil rights and religious organizations, on hold pending the outcome in Strauss and its companion cases.

The court allowed proponents of Proposition 8 to intervene in the case to attempt to defend its validity.

In its November 19 order, the court directed the parties to brief the following issues:

(1) Is Proposition 8 invalid because it is a revision rather than an amendment to the California Constitution?

(2) Does Proposition 8 violate the separation of powers doctrine under the California Constitution?

(3) If Proposition 8 is not unconstitutional , what is its effect, if any, on the marriages of same-sex couples performed before its adoption?

On Friday, December 19, 2008, the intervenors filed their brief and the state filed its brief.

Unsurprisingly, the proponents of Proposition 8 claim it is a valid amendment. They also argue that it retroactively invalidates marriages of same-sex couples performed before its adoption.

The state Attorney General argues Proposition 8 is invalid because the initiative process may not deprive persons of certain fundamental rights without a compelling justification, which is not present in this case. The state also argues that even if it is valid, Proposition 8 is not retroactive.