In response to the bad constitutional arguments being used to challenge the cap on the SALT deduction, I’ve some people arguing that even if Shelby County is wrong, it should be mobilized by liberals to oppose policies they don’t like. But this has no chance of actually working. There are obvious problems with some of the underlying assumptions — the theoretically and empirically false claim that the Supreme Court unilaterally and permanently settles disputes over constitutional meaning, vastly overstating the extent to which the Supreme Court considers itself bound by its own precedents.
But, really, this is Shelby County we’re talking about here — you don’t even need a very sophisticated view of how constitutional norms are constructed or a very strong version of legal realism to see that the idea that the holding can somehow force conservatives to reach policy outcomes they don’t want to is silly. The Equal Sovereign Dignitude of the States isn’t a serious constitutional principle — it’s ad hoc bullshit John Roberts came up with to reach a specific policy outcome he had been explicitly seeking since he was in Reagan’s DOJ. The holding therefore imposes no meaningful constraint on any judge in any other case. To nudge Judge Posner’s metaphor, it doesn’t just rest on air; it is air. It doesn’t apply to any statute in which the states are being treated in formally equal matter. And even in cases where states are explicitly being treated differently, Shelby County doesn’t suggest that this is always a constitutional violation — indeed, the (self-refuting) holding of the case is that Section 4 of the Voting Rights Act was constitutional at the time of its enactment, but is no longer constitutional because it was too effective at accomplishing the ends Congress sought when exercising its authority under the 15th Amendment. Roberts’s opinion identifies no standard of review to be used to determine when the “equal sovereignty” of the states can be abrogated by Congress and when it cannot, leaving any judge free to reach any outcome she desires in any future case without being even formally inconsistent with Shelby County. (Even if the Voting Rights Act came before a court in the precise form it was enacted in 2006, a judge could find that Section 4 was now constitutional again because of changing conditions without being formally inconsistent with the holding in Shelby County.)
Therefore, as long as there is a conservative median vote on the Supreme Court, Shelby County has no chance of being used for progressive purposes; it doesn’t require, even in theory, any justice to reach any outcome they would prefer not to. And the next Supreme Court with a liberal median vote should and will overrule Shelby County at the earliest opportunity because it is both transparently wrong and pernicious. And this is what liberals should be saying about Shelby County, not trying to come up with triple-bank-shot schemes for using it for progressive ends that have a 0% chance of actually working.