Here's the key to the California same-sex marriage decision:

"Although all parties in this proceeding agree that the right to marry constitutes a fundamental right protected by the state Constitution, there is considerable disagreement as to the scope and content of this fundamental state constitutional right."

"First, we must determine the nature and scope of the "right to marry" - a right that past cases establish as one of the fundamental constitutional rights embodied in the California Constitution. 

"As discussed below, upon review of the numerous California decisions that have examined the underlying bases and significance of the constitutional right to marry (and that illuminate why this right has been recognized as one of the basic, inalienable civil rights guaranteed to an individual by the California Constitution), we conclude that, under this state's Constitution, the constitutionally based right to marry properly must be understood to encompass the core set of basic substantive legal rights and attributes traditionally associated with marriage that are so integral to an individual's liberty and personal autonomy that they may not be eliminated or abrogated by the Legislature or by the electorate through the statutory initiative process. These core substantive rights include, most fundamentally, the opportunity of an individual to establish - with the person with whom the individual has chosen to share his or her life - an officially recognized and protected family possessing mutual rights and responsibilities and entitled to the same respect and dignity accorded a union traditionally designated as marriage. As past cases establish, the substantive right of two adults who share a loving relationship to join together to establish an officially recognized family of their own - and, if the couple chooses, to raise children within that family - constitutes a vitally important attribute of the fundamental interest in liberty and personal autonomy that the California Constitution secures to all persons for the benefit of both the individual and society.

"Under the strict scrutiny standard, unlike the rational basis standard, in order to demonstrate the constitutional validity of a challenged statutory classification the state must establish (1) that the state interest intended to be served by the differential treatment not only is a constitutionally legitimate interest, but is a compelling state interest, and (2) that the differential treatment not only is reasonably related to but is necessary to serve that compelling state interest. Applying this standard to the statutory classification here at issue, we conclude that the purpose underlying differential treatment of opposite-sex and same-sex couples embodied in California's current marriage statutes - the interest in retaining the traditional and well-established definition of marriage - cannot properly be viewed as a compelling state interest for purposes of the equal protection clause, or as necessary to serve such an interest.

     "A number of factors lead us to this conclusion. First, the exclusion of same-sex couples from the designation of marriage clearly is not necessary in order to afford full protection to all of the rights and benefits that currently are enjoyed by married opposite-sex couples; permitting same-sex couples access to the designation of marriage will not deprive opposite-sex couples of any rights and will not alter the legal framework of the institution of marriage, because same-sex couples who choose to marry will be subject to the same obligations and duties that currently are imposed on married opposite-sex couples. Second, retaining the traditional definition of marriage and affording same-sex couples only a separate and differently named family relationship will, as a realistic matter, impose appreciable harm on same-sex couples and their children, because denying such couples access to the familiar and highly favored designation of marriage is likely to cast doubt on whether the official family relationship of same-sex couples enjoys dignity equal to that of opposite-sex couples. Third, because of the widespread disparagement that gay individuals historically have faced, it is all the more probable that excluding same-sex couples from the legal institution of marriage is likely to be viewed as reflecting an official view that their committed relationships are of lesser stature than the comparable relationships of opposite-sex couples. Finally, retaining the designation of marriage exclusively for oppositesex couples and providing only a separate and distinct designation for same-sex couples may well have the effect of perpetuating a more general premise - now emphatically rejected by this state - that gay individuals and same-sex couples are in some respects "second-class citizens" who may, under the law, be treated

differently from, and less favorably than, heterosexual individuals or opposite-sex couples. Under these circumstances, we cannot find that retention of the traditional definition of marriage constitutes a compelling state interest. Accordingly, we conclude that to the extent the current California statutory provisions limit marriage to opposite-sex couples, these statutes are unconstitutional.

"The recent comprehensive domestic partnership legislation constitutes the culmination of a gradual expansion of rights that have been made available in this state to same-sex couples who choose to register as domestic partners.

"In light of all of these circumstances, we conclude that retention of the traditional definition of marriage does not constitute a state interest sufficiently compelling, under the strict scrutiny equal protection standard, to justify withholding that status from same-sex couples."