The California Supreme Court decision striking down California's opposite-sex-only-marriage rule helps illustrate, I think, what I call "legislative-judicial slippery slopes" — the tendency of some legislative decisions to affect future judicial decisions, even judicial decisions that cover territory considerably beyond the original statute.

Now this tendency is often pooh-poohed when the initial legislative decision takes place — and of course that makes sense, because the decision's backers want to argue that the decision is quite narrow. Thus, for instance, consider:

1. Editorial, A Vote Against Hate, Louisville Courier-J., Feb. 3, 1994, at 6A, arguing that the claim that a hate crime law "would lead to acceptance of gay marriages" was "arrant nonsense."

2. Editorial, A Gay-Protection Forum, Boston Globe, Oct. 15, 1989, at A30: "Nor does passage of the bill [that bans sexual orientation discrimination in various commercial transactions] put Massachusetts on a 'slippery slope' toward [same-sex marriage or domestic benefit] rights."

3. Phil Pitchford, Council Members Wary of Partner Registry, Riverside Press-Enterprise (quoting Riverside Human Relations Commission member Kay Smith): "Those that truly have a problem with homosexuality will see [a domestic partnership proposal] as part of the 'slippery slope' [toward same-sex marriages] .... But, this legislation needs to be looked at on the face value of what it is, and it really does very little."

Yet consider how the California Supreme Court used the legislative enactment of these sorts of laws as part of its basis for deciding that the right to marry should be seen as encompassing same-sex marriage:

There can be no question but that, in recent decades, there has been a fundamental and dramatic transformation in this state’s understanding and legal treatment of gay individuals and gay couples. California has repudiated past practices and policies that were based on a once common viewpoint that denigrated the general character and morals of gay individuals, and at one time even characterized homosexuality as a mental illness rather than as simply one of the numerous variables of our common and diverse humanity. This state’s current policies and conduct regarding homosexuality recognize that gay individuals are entitled to the same legal rights and the same respect and dignity afforded all other individuals and are protected from discrimination on the basis of their sexual orientation, and, more specifically, recognize that gay individuals are fully capable of entering into the kind of loving and enduring committed relationships that may serve as the foundation of a family and of responsibly caring for and raising children.

[Footnotes to above: See, for example, Civil Code section 51 (barring sexual orientation discrimination in the provision of services by any business establishment); Government Code sections 12920 (barring sexual orientation discrimination in employment), 12955 (barring sexual orientation discrimination in housing), 11135, subdivision (a) (barring sexual orientation discrimination in any program operated by, or that receives any financial assistance from, the state); Gay Law Students Assn. v. Pacific Tel. & Tel. Co. (1979) 24 Cal.3d 458, 466-475 (Gay Law Students) (Cal. Const. prohibits sexual orientation discrimination by public utility). See, for example, sections 297 et seq., 9000, subdivisions (b), (g); Welfare & Institutions Code section 16013, subdivision (a); Sharon S. v. Superior Court (2003) 31 Cal.4th 417; Elisa B. v. Superior Court, supra, 37 Cal.4th 108....]

Similar arguments were made by the Massachusetts Supreme Judicial Court and the Vermont Supreme Court, when they decided that their state constitutions should be read as recognizing a right to same-sex marriage (Massachusetts) and same-sex domestic partnership benefits (Vermont).

Now the California Supreme Court majority does say that "our reference to numerous statutes demonstrating California’s current recognition that gay individuals are entitled to equal and nondiscriminatory legal treatment does not suggest that an individual’s entitlement to equal treatment under the law — regardless of his or her sexual orientation — is grounded upon the Legislature’s recent enactment of the Domestic Partner Act or any other legislative measure. The capability of gay individuals to enter into loving and enduring relationships comparable to those entered into by heterosexuals is in no way dependent upon the enactment of the Domestic Partner Act; the adoption of that legislation simply constitutes an explicit official recognition of that capacity. Similarly, the numerous recent legislative enactments prohibiting discrimination on the basis of sexual orientation were not required in order to confer upon gay individuals a legal status equal to that enjoyed by heterosexuals; these measures simply provide explicit official recognition of, and affirmative support for, that equal legal status."

Yet the majority's citing those past legislative decisions — and going on to say that "Indeed, the change in this state’s past treatment of gay individuals and homosexual conduct is reflected in scores of legislative, administrative, and judicial actions that have occurred over the past 30 or more years. (See, e.g., Stats. 1975, ch. 71, §§ 7, 10, pp. 133, 134 [revising statutes criminalizing consensual sodomy and oral copulation]; Governor’s Exec. Order No. B-54-79 (Apr. 4, 1979) [barring sexual-orientation discrimination against state employees]; Morrison v. State Board of Education (1969) 1 Cal.3d 214 [homosexual conduct does not in itself necessarily constitute immoral conduct or demonstrate unfitness to teach].)" — means that the Justices in the majority must see legislative decisions as relevant. Maybe at least one Justice of the 4-to-3 majority was indeed swayed by the body of legislative pro-gay-rights judgment; or even if the argument was makeweight, the majority must think that some of the readers would be swayed by these legislative judgments. And these legislative judgments are seen as relevant even in an area (same-sex marriage) different from that in which the initial legislative judgments took place.

Of course, some people might like this slippery slope, because they like what's on the bottom. (See Deb Price, Marriage Is the Only Acceptable Option, S.J. Mercury News, May 23, 2002: "When Hawaii's steps toward legalizing gay marriage led to a backlash in Congress and many states in the mid-'90s, some gay-rights advocates felt the need to pooh-pooh the 'slippery slope' argument by foes that we'd ultimately try to push beyond any piecemeal rights thrown our way and would be satisfied with nothing less than full marriage. But not anymore. 'Our foes kept saying, 'This is a slippery slope to marriage,' and we kept nodding our heads, 'Yep,'' says [Anne] Stanback, unabashedly embracing marriage as the goal, just as do the movement's two top political groups, the Human Rights Campaign and the National Gay and Lesbian Task Force.") I myself support recognition of same-sex marriage as a policy matter. Still others may disapprove of the bottom of the slope, but might see some of the steps down it as morally imperative. (The decriminalization of same-sex sexual conduct, which the California Supreme Court majority cited as evidence of a "change in this state’s past treatment of gay individuals and homosexual conduct," is likely the best example.)

But it seems to me that decisions such as the California, Massachusetts, and Vermont ones illustrate that it's a mistake to just factually dismiss the claims that slippage is possible. When we're dealing with a legal system that's built on analogy and precedent (both binding precedent and persuasive precedent), slippery slope risks have to be taken seriously.