Skidmore Deference for Agency Amicus Briefs?

Supreme Court denies cert in DuPont v. Smiley

This is probably the least important news of the day, but the Supreme Court has denied cert in DuPont v. Smiley, which raised the question (among others) of whether an agency is entitled to Skidmore "deference" for interpretations advanced for the first time in litigation. Justice Gorsuch (joined by Chief Justice Roberts and Justice Thomas) issued a statement respecting the denial of cert:

The issue surely qualifies as an important one. After all, Skidmore deference only makes a difference when the court would not otherwise reach the same interpretation as the agency. And a number of scholars and amici have raised thoughtful questions about the propriety of affording that kind of deference to agency litigation positions. For example, how are people to know if their conduct is permissible when they act if the agency will only tell them later during litigation? Don't serious equal protection concerns arise when an agency advances an interpretation only in litigation with full view of who would benefit and who would be harmed? Might the practice undermine the Administrative Procedure Act's structure by incentivizing agencies to regulate by amicus brief, rather than by rule? Should we be concerned that some agencies (including the one before us) have apparently become particularly aggressive in "attempt[ing] to mold statutory interpretation and establish policy by filing 'friend of the court' briefs in private litigation"?

(The amici who filed briefs were Cato and the Pacific Legal Foundation.)

It's not obvious how much difference this makes, since Skidmore "deference" is widely considered to be a weak form of deference, and I've even put "deference" in quotes here because Skidmore just tells courts to pay some respect to agencies' interpretations (to the extent those interpretations are persuasive) as the courts come to their own conclusion. (In this way, Skidmore "deference" differs from Chevron deference, which is a true form of deference: it reflects a (presumed) implied congressional delegation of interpretive power to agencies and thus takes some interpretive power away from courts.) Still, this is an interesting administrative law development for those who keep track of such things.

P.S. I see that Jonathan has beat me to this.

P.P.S. That Justice Alito didn't join this statement may not tell us much about his views, because it says that he didn't consider the cert petition at all: perhaps he was conflicted out? (It's a Third Circuit case involving labor law, and his sister is a Third Circuit labor lawyer -- maybe that has something to do with it, though I'm not motivated enough to research the firms involved.)