As usual, a Slate columnist has gone too far. I don't know what it is about Slate that encourages extreme positions. This is not to say that they shouldn't be published, because they add to the value of public discourse. It is only to wonder about the willingness of the editorial staff to question illogic. Richard Ford asserts that "[u]ntil a court decides otherwise, then, local officials are bound to uphold state law." Professor Solum rebuts this persuasively:
City officials, like judges, are obligated by the law itself. This means that when the responsible city official believes that an ordinance or is unconstitutional, she should not enforce it. Ford takes the position that the rule of law is virtually identical with the rule of judges—a proposition that is unsound as a matter of political and legal theory. The rule of law requires that we adhere to the law—and not only to what judges have already pronounced the law to be.
"Ford on the Duty to Obey the Constitution" (23 Feb 2004).
To borrow an approach from Slate, let's look at the extreme case. A military officer is even more bound to follow directives than is a "local official." Local officials, after all, aren't subject to court martial for failure to obey an order. Consider an order to raze a village in north-central Iraq. The order itself doesn't say so, but the superior officer—let's say the battalion commander, a lieutenant colonel—indicates to the company commander who will be charged with the task that this means killing civilians because they're almost all al Q'aida members, or at least sympathizers. In turn, the company commander (a captain) parrots this to the platoon leader, a second lieutenant barely out of Annapolis (we'll pretend these are Marines, not Army). The lieutenant blindly follows the order, resulting in the deaths of approximately 125 civilians.
Under Ford's theory, the lieutenant did the right thing. Those with long memories may recall something similar in the 1960s. As Lt William Calley and Capt Ernest Medina found out, their defense that they were "only following orders" was improper both on factual grounds—they didn't present much evidence that such orders had actually been given, although later investigation indicates that they most probably were—and legal grounds. The military judge ruled that even if such orders had been given, they were so clearly unlawful that an officer under the pressure of a combat zone was still required to disobey them. This ruling was undisturbed on appeal. Under Ford's theory, though, the lieutenant (and captain) would not be guilty of war crimes, but would be guilty of disobeying an order.
I'll freely admit that I have stacked the deck here a bit. The military provision actually pertains to "lawful written" orders and "dereliction of duty." In other words, even in the rigid environment of the military, one is required to at least make a surface inquiry into whether an order is lawful. This points out the reality of what military officers, and local officials, must do: they must use their judgment to apply potentially conflicting directives from higher authorities to particular factual circumstances. Whether the local officials in San Francisco are correct in their conclusions is irrelevant; Ford would make them incorrect in their inquiry. Nobody has presented evidence that the San Francisco officials have made their stand in bad faith—quite the opposite: they have pointed to a conflicting authority even higher than the statute itself. That is the opposite of what the lieutenants described above did. Ford's invocation of John Hart Ely is unavailing, because it is precisely opposed to the particular examples Ely used in forming his theory. Remember, "Jim Crow" wasn't just a practice—it was state law.
The local officials in San Francisco have been put in an untenable position by conflict between two provisions from higher authority. They have made an explicit choice of which one controls, and then adapted their actions to that choice. Whether one agrees with their interpretation is a separate question; they did their duty as local officials. If their choice proves to be egregiously wrong, there are retrospective remedies for the particular choice they made (the marriage licenses can be retroactively revoked and the officials removed from office). But criticizing them for having the temerity to act without judicial guidance when there is no judicial guidance on the particular issue is not just unrealistic; Ford's position arguably violates both the US and California constitutions. It sure as hell violates common sense. That's why we have local officials and not automatons.