Michael M. v. Superior Court of Sonoma County

A dissenting opinion by Justice Brennan stated that Rehnquist's opinion placed too much emphasis on California's goal of preventing teenage pregnancy and not enough emphasis on whether the discrimination on the basis of sex was warranted and related to that goal. The dissenters argued that the state did not provide enough evidence to establish the legitimacy of its goal (preventing teenage pregnancy), nor did it prove the relationship between the gender-based discrimination and that objective. They looked for California to provide evidence that there are fewer teenage pregnancies under the statutory rape law than there would be if the law were gender neutral, as well as evidence that because it punishes only males, it more effectively deters underaged women from having sexual intercourse. The state did not provide that kind of evidence, and therefore the dissenting justices were not convinced.

The dissenting opinion also pointed out that at the time, there were 37 states which have gender-neutral statutory rape laws, and that California had revised other sections of the Penal Code to make them gender-neutral. They also stated that common sense dictates that gender-neutral laws are potentially greater deterrents for underage sexual activity, since it makes both men and women subject to criminal punishment, therefore impacting twice as many potential violators. Justice Stevens, in a separate dissent, suggested that there is no reason to exempt a woman from the scope of the law, when the woman is capable of using her own judgment of whether or not to assume the risk of sexual intercourse.