Our responsibility  is to protect constitutional rights of individuals from legislative enactments that have denied those rights, even when the rights have not yet been broadly accepted, were at one time unimagined, or challenge a deeply ingrained practice or law viewed to be impervious to the passage of time....As Justice Oliver Wendell Holmes poignantly said, “It is revolting to have no better reason for a rule of law than that so it was laid down in the time of Henry IV. It is still more revolting if the grounds upon which it was laid down have vanished long since, and the rule simply persists from blind imitation of the past.”
....[E]qual protection before the law demands more than the equal application of the classifications made by the law. The law itself must be equal. [...] In other words, to truly ensure equality before the law, the equal protection guarantee requires that laws treat all those who are similarly situated with respect to the purposes of the law alike.
....It is true the marriage statute does not expressly prohibit gay and lesbian persons from marrying; it does, however, require that if they marry, it must be to someone of the opposite sex. Viewed in the complete context of marriage, including intimacy, civil marriage with a person of the opposite sex is as unappealing to a gay or lesbian person as civil marriage with a person of the same sex is to a heterosexual. Thus, the right of a gay or lesbian person under the marriage statute to enter into a civil marriage only with a person of the opposite sex is no right at all....By purposefully placing civil marriage outside the realistic reach of gay and lesbian individuals, the ban on same-sex civil marriages differentiates implicitly on the basis of sexual orientation.
That's nicely and plainly said. Very midwestern. The court then went through the usual list of reasons for banning gay marriage (maintaining traditional marriage, promotion of optimal environment to raise children, promotion of procreation, promoting stability in opposite-sex relationships) and concluded that none of them had enough substance to overcome obvious discrimination against a relatively powerless class. And that was that.
So for now, anyway, Iowa has gay marriage and California doesn't. Who would have guessed?