Cases decided in Kisor's wake are already applying the new deference framework in the Chevron context. See, e.g., Braeburn Inc. v. FDA, 389 F. Supp. 3d 1 (D.D.C. 2019); E. Bay Sanctuary Covenant v. Barr, 385 F. Supp. 3d 922, 939 (N.D. Cal. 2019), order reinstated, 391 F. Supp. 3d 974 (N.D. Cal. 2019). I wish they'd knock it off, though. As the Chief Justice put it in his concurring opinion in Kisor:
Issues surrounding judicial deference to agency interpretations of their own regulations are distinct from those raised in connection with judicial deference to agency interpretations of statutes enacted by Congress. See Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984). I do not regard the Court’s decision today to touch upon the latter question.
That got me thinking about all the ways the standards differ. I discuss briefly some of the differences that I could think of off the top of my head, but I'm sure I'm missing many--perhaps even some very important ones. If you can think of any, please let me know in the comments.
First, they have different theoretical justifications.
Although both doctrines rest on the Court's view that agencies are more politically accountable and more capable subject-matter experts than courts, Part II.A. of Justice Kagan's opinion in Kisor, which was not joined by a majority of the Justices, also assumes that the agency that wrote the ambiguous rule is in the best position to say what it means. That justification couldn't possibly apply in the Chevron context because Chevron involves judicial deference to agency's interpretations of statutes (legal texts the agency didn't write).
Second, Chevron requires courts to attribute congressional intent to something Congress controls (ambiguity in statutes), whereas Kisor requires courts to attribute congressional intent to something agencies control (ambiguity in regulations).
Both doctrines treat textual ambiguity as evidence of Congress's intent to delegate interpretive authority to the agency instead of the courts. Because Congress controls the text of statutes, there is some intuitive basis for the presumption in the Chevron context (though I think it's still questionable). In the Auer/Kisor context, though, it doesn't make sense. Congress doesn't write regulations; agencies do. Thus, the presence of an ambiguity in a regulation says nothing about Congress's intent. If anything, it says something about the intent of the agency. Put differently, Congress controls or at least can control how courts will evaluate the signals of its own intent in the Chevron context, but Kisor permits agencies to control the Court's view of Congress's intent.
I can't move to the next point without emphasizing that while the Justices who joined Part II.A. of Justice Kagan's Kisor opinion may believe it's a great idea to rely on a law's author to tell us what it means, Blackstone didn't. 1 William Blackstone, Commentaries *58. Nor did the Framers. The Federalist No. 81, at 483 (Alexander Hamilton) (Clinton Rossiter ed., 1961). Nor does the Supreme Court in most contexts. See, e.g., Mistretta v. United States, 488 U.S. 361, 371-74 (1989); Morrison v. Olson, 487 U.S. 654, 680-81 (1988); Commodity Futures Trading Comm'n v. Schor, 478 U.S. 833, 847-57 (1986).
Third, Chevron doesn't apply to (some) "major questions." It remains unclear whether the same is true of Kisor.
At least since King v. Burwell, 135 S. Ct. 2480 (2015), Chevron hasn't applied to questions of extraordinary political or economic importance. If Congress wanted to delegate such important questions to agencies (instead of courts), the Court explained, "it surely would [do] so expressly." Id. at 2489. The Court has not told us whether that restriction in the Kisor/Auer context.
Fourth, the so-called "Step-Zero" analysis applicable under Chevron differs from the "similar" standard applicable under Kisor.
In the Chevron context, the Court won't defer without first asking (1) whether Congress gave the agency the power to interpret the statute with the force and effect of law and (2) whether the agency interpretation at issue was itself the exercise of that power. Mead. Kisor purported to adopt a "similar" though not "identical" framework for Auer deference, but it never explained the distinction between the two standards. So what are the relevant differences?
While I'm sure these aren't the only ones, the most obvious differences to me are that (1) the agency doesn't need to speak with the force and effect of law when interpreting a regulation to receive Kisor deference, and (2) Mead describes this "Step Zero" analysis as a threshold inquiry necessary to determine whether Chevron applies at all, whereas Kisor appears to instruct courts to apply its analogous framework after the Court has exhausted the traditional tools of construction and determined the regulation at issue is genuinely ambiguous. There's much more to say here.
Fifth, "traditional tools of statutory construction," which courts must apply in the Chevron context, may differ from the "traditional tools of construction" applicable in the Kisor context.
Chevron requires courts to exhaust the "traditional tools of statutory construction" before declaring a statute ambiguous; Kisor instructs courts to exhaust the "traditional tools of construction." While courts disagree over what constitutes the full list of "traditional tools of statutory construction," at least we know what the relevant alternatives are. As far as I know, no one has ever even attempted to list all the traditional tools of construction. Who knows what those are.
Sixth, Skidmore plays a different role.
Mead tells us that when the Step Zero inquiry reveals that Chevron doesn't apply, courts apply Skidmore instead. Kisor similarly explains that "when the reasons for that presumption do not apply, or countervailing reasons outweigh them, courts should not give deference to an agency’s reading, except to the extent it has the 'power to persuade.'" (quoting Skidmore). Notice, though, that Skidmore becomes relevant in the Chevron context before the famous two-stop even begins, whereas, in the Kisor context it apparently arises later.
Furthermore, by the time a court reverts to Skidmore in the Kisor context, there might not be much meat left on the Skidmore chicken wing. By the time a court figures out that "the reasons for th[e] presumption do not apply, or countervailing reasons outweigh them," under the Kisor framework, it may have already done quite an exhaustive analysis, including (a) rigorous application of all traditional tools of construction, (b) some sort of reasonableness analysis, (c) an inspection of the interpretation's authoritativeness, (d) determining whether the interpretation is expertise-based, (e) assessing whether the interpretation is the result of the agency's fair and considered judgment, etc. Having journeyed that far to determine that deference is inappropriate, it's hard to imagine that there would be much left to consider under Skidmore. If there is anything, the Court doesn't say what it is.
Seventh, it's not clear how Kisor and State Farm (APA arbitrary and capricious anslysis) are supposed to interact.
Some say that Chevron Step Two is interchangeable with arbitrary-and-capricious review. If the same is true of some "step" of the Kisor framework, it's not obvious which one it is. Of course, if Kisor has steps at all, it's not clear how many there are or if judges must march through them in a particular order.