Suppose a contemporary national majority were to favor same-sex marriage, and the Supreme Court were to hold that a federal-law limitation of “marriage” to the union of opposite-sex individuals violated the Equal Protection component of the Due Process Clause of the Fifth Amendment. Would it be fair to describe that holding as counter-majoritarian? Not with time slicing. Without time slicing, the ruling would obviously be counter-majoritarian.
By this standard, couldn’t you say that any new legislation enacted by a democratically elected and satisfactorily representative legislature is counter-majoritarian? Or even that a plebiscite changing the duly enacted pre-existing law of the relevant jurisdiction is counter-majoritarian?
Yes, new legislation can be counter-majoritarian by this measure. And I do not mean to imply that it’s necessarily bad to be counter-majoritarian in this backward-looking way. A contemporary majority may suffice to make a change. With respect to constitutional interpretation, however, the typical claim is not that the new and true interpretation is a change, but rather that it is the interpretation that has been right all along. To suggest that such a change is legitimate because majoritarian seems confused.