n17 The Court dangles the possibility that Gregory itself is somehow pertinent to this case, but that cannot be so. There, invoking principles of constitutional avoidance, we recognized a "plain statement" rule, whereby Congress could supplant State powers "reserved under the Tenth Amendment" and "at the heart of representative government," only by making its intent to do so unmistakably clear. Unlike a State's authority to "determine the qualifications of their most important government officials," (e.g., to enforce a retirement age for state judges mandated by the state constitution, at issue in Gregory), the authority of the States in defining and adjusting the relations between debtors and creditors has never been plenary, nor could it fairly be called "essential to their independence." In making the improbable contrary assertion, the Court converts a stray phrase in American Land Co. v. Zeiss, 219 U.S. 47, 55 L. Ed. 82, 31 S. Ct. 200 (1911), which upheld against substantive Due Process challenge the power of a State to legislate with respect to land titles (California's effort to restore order after title records had been destroyed in the calamitous 1906 San Francisco earthquake) into a pronouncement about the allocation of responsibility between the National Government and the States. Cf. Cipollone v. Liggett Group, Inc., 505 U.S. (1992) (slip op., at 3-4) (SCALIA, J., concurring in part) (emphasizing the inapplicability of "clear-statement" rules to ordinary pre-emption cases).