When the Supreme Court decides a case, the parties of that case are bound to that decision, as are those in parallel circumstances. But the Court cannot establish law by extending beyond that strict limit whatever "principle" they've suddenly created.
The current struggle between the friends of the Constitution and those who despise it and them will end in one of two places: either the reasonable and the decent will assert themselves and reestablish the rule of law, common sense, and basic decency, or there will be no barriers to any deviant impulse's being enshrined as "law."
Clearly anyone seeking a same-sex marriage license in a state who was not party to the Obergefell suit falls under what Lincoln would call a “parallel case.” But what about someone who runs to federal court or a state marriage license bureau, and holds up Obergefell’s doctrine of “dignity” on behalf of, say, polygamy? Must the court or marriage license bureau shrug their shoulders and say, “Well—I guess so”?
When Lincoln arrived in the White House in 1861, he found two executive branch decisions to which he objected. A free black man in Boston had applied to the State Department for a passport to travel to France, which the State Department had denied on the ground that the Supreme Court, in Dred Scott, had declared that blacks could not be citizens because blacks “had no rights which the white man was bound to respect.” And in Philadelphia, a free black man had applied to the Patent Office for an invention, and been denied on the same ground. Lincoln ordered both decisions reversed.
I often tell this story to my students in classes on the Constitution, with the question appended: “Was Lincoln defying the Supreme Court? Did he act unconstitutionally?” It is amazing—and depressing—that the overwhelming majority of my students get the answer wrong. Such is an example of how deep the idea of judicial supremacy—“the Constitution is what the Supreme Court says it is,” as the Court self-congratulated in Cooper v. Aaron—has crept into the public mind today.
Look again at Lincoln’s careful language in that passage above. He is saying that the reasoning of Dred Scott must be respected as to the parties of that particular case and in parallel cases (i.e., a slave owner who brings his slave into a free state, as Dred Scott’s owner had done). But in his decision to reverse the executive branch decisions supposedly based on Dred Scott in circumstances that were not parallel—both were free blacks in free states, with no one asserting ownership claims to them—Lincoln was asserting that the executive branch was not obligated to extend the principle of the Dred Scott case more broadly. The Constitution belongs to all three branches of government, each of which may assert its constitutional prerogatives in its own sphere—pending a legal challenge in the courts that concludes otherwise.