Why does the Supreme Court use different language for remands to state court and federal court?

The former uses "further proceedings not inconsistent with this opinion" and the latter uses "further proceedings consistent with this opinion."

Last week, I blogged about a persnickety question that Supreme Court practitioners often litigate: when does a Supreme Court judgment become effect. In this post I will raise another curiosity of Supreme Court practice: the Justices use different language when a case is remanded to state court and federal court.

Consider the language used this term in Espinoza v. Montana Department of Revenue. This case reversed the decision of the Montana Supreme Court. The opinion concluded:

The judgment of the Montana Supreme Court is reversed, and the case is remanded for further proceedings not inconsistent with this opinion.

Contrast that language with the conclusion in Liu v. SEC. This case reversed a decision from the Ninth Circuit:

For the foregoing reasons, we vacate the judgment below and remand the case to the Ninth Circuit for further proceedings consistent with this opinion.

State decisions are "remanded for further proceedings not inconsistent with this opinion." Federal decisions are remanded for "further proceedings consistent with this opinion." The latter language seems stricter than the former language. Perhaps the Court wishes to give the state courts more leeway in implementing a Supreme Court decision. Federal courts, in contrast, have less latitude to implement a Supreme Court decision.

I don't know how or when this practice arose. But it seems to subtly account for basic principles of federalism. Of course, under Martin v. Hunter's Lessee, state courts are bound by the Supreme Court's judgments. At least the Justices can be nice about it.