In resolving the question, the majority paid Skidmore deference to the interpretive guidance issued by the Equal Employment Opportunity Commission. But the EEOC's guidance lacked the requisite 'power to persuade'. (see slip op., footnote 4)
The interesting aspect is that the term "supervisor" does not appear in the governing statute. Rather, it was a creation of the Court. Any deference here was to the EEOC's interpretation of terminology of the Court, not Congress. Does affording deference to an administrative interpretation of a judicial decision usher in a new era?
In dissent, Ginsburg J. was more circumspect:
Any deference was thus tied to a statutory provision. A few steps removed, perhaps, but hardly a quantum leap.Respondent’s amici maintain that the EEOC Guidance is ineligible for deference under Skidmore v. Swift & Co., 323 U. S. 134 (1944), because it interprets Faragher and Burlington Industries, Inc. v. Ellerth, 524 U. S. 742 (1998), not the text of Title VII. See Brief for Society for Human Resource Management et al. 11–16. They are mistaken. The EEOC Guidance rest s on the employer liability framework set forth in Faragher and Ellerth, but both the framework and EEOC Guidance construe the term “agent” in 42 U. S. C. §2000e(b). (see slip op., footnote 4)
For my own part, I do not have any great difficulty with deference to administrative interpretations of judicial decisions. Just as with statutory provisions, administrative agencies may be better placed to determine how best judicial decisions are applied 'on the ground'. And where a judicial decision is open to more than one reading, there is little justification for a reviewing court to come back and have another bite without taking serious account of the administrative decision-maker's interpretation.
For a recent comment on the importance of interpreting judicial decisions, see Jaworski, Originalism All the Way Down: Or, the Explosion of Progressivism.