Gay couples have been legally married in Massachusetts, to what appears to be increasing public acceptance (or indifference) since 2004. Gay marriage did not damage the social fabric (or undermine heterosexual marriage,) as opponents hysterically predicted, and public debate moved on (to wind farms, gambling, sales taxes, and, most recently, a media driven fracas over Senator Kerry's yacht.)
It is worth stressing, of course, that this victory in Massachusetts began with a landmark decision by the state's Supreme Judicial Court affirming the right of gay people to marry under the state constitution (a decision for which retiring Chief Justice Margaret Marshall has been justly celebrated.) The battle for racial equality (under law, if not custom) was won partly in the courts beginning with Brown v Board of Education and including, a decade later, Loving v Virginia, the Supreme Court decision that struck down bans on interracial marriage. So I'm not denying, much less decrying, the role of the judiciary in securing civil rights, by enforcing constitutional guarantees of equality.
But, the Supreme Court's ruling invalidating inter-racial marriage bans under the federal constitution followed years of progress by the states (beginning with a 1948 decision by the California courts striking down a state ban.) We have not progressed nearly as far in legalizing gay marriage. Indeed, while the Supreme Court has confirmed the fundamental rights of gay people in two crucial cases, it has never held that sexual orientation is a protected category, like race, sex, ethnicity, or religion. In other words, it has not applied the same high standards of review to cases involving discrimination against gay people that it applies to cases involving racial, sexual, or religious discrimination.
In Lawrence v Texas, the Court held that state laws criminalizing consensual gay sex violated due process guarantees of liberty. In Romer v Evans, the Court struck down an amendment to the Colorado constitution barring localities from passing gay rights laws, ruling that the amendment was not rationally related to a legitimate state purpose. This "rational relation" test is the most permissive standard of review in cases challenging the constitutionality of state or federal laws; it's a standard reflecting judicial deference to legislative decision-making, pursuant to which laws are usually upheld - but not in recent gay rights cases. In striking down Prop 8, Judge Walker invoked this lower (or lowest) standard of review, as did Judge Tauro, when he struck down parts of the federal Defense of Marriage Act.
Why is this relevant? The failure to recognize gay people as a protected class, subjecting discrimination against them to strict standards of judicial review, the repeated invalidation of anti-gay laws as simply irrational, enhances the claim that these cases represent abuses of judicial discretion, that judges are substituting their values (and findings of fact) for the values and findings of legislators. I am not endorsing this argument (and I agree that discriminating on the basis of sexual orientation is simply irrational.) I am simply pointing out that the judicial activism argument may not be easily dismissed.