In a lengthy discourse on where our administrative state went wrong, Justice Thomas draws the root of many of our problems to the Progressive Era:

Fundamentally, the argument about agency expertise is less about the expertise of agencies in interpreting language than it is about the wisdom of according agencies broad flexibility to administer statutory schemes.6

6 Many decisions of this Court invoke agency expertise as a justification for deference. This argument has its root in the support for administrative agencies that developed during the Progressive Era in this country. The Era was marked by a move from the individualism that had long characterized American society to the concept of a society organized for collective action. See A. Link, Woodrow Wilson and the Progressive Era 1910–1917, p. 1 (1954). That move also reflected a deep disdain for the theory of popular sovereignty. As Woodrow Wilson wrote before he attained the presidency, “Our peculiar American difficulty in organizing administration is not the danger of losing liberty, but the danger of not being able or willing to separate its essentials from its accidents. Our success is made doubtful by that besetting error of ours, the error of trying to do too much by vote.” Wilson, The Study of Administration, 2 Pol. Sci. Q. 197, 214 (1887). In President Wilson’s view, public criticism would be beneficial in the formation of overall policy, but “a clumsy nuisance” in the daily life of Government—“a rustic handling delicate machinery.” Id., at 215. Reflecting this belief that bureaucrats might more effectively govern the country than the American people, the progressives ushered in significant expansions of the administrative state, ultimately culminating in the New Deal. See generally M. Keller, Regulating a New Economy: Public Policy and Economic Change in America, 1900–1933 (1990).

Thomas adds that fortunately, the Constitution “protects us from ourselves,” regardless of what the Progressives wrought.

“But policy arguments supporting even useful ‘political inven- tions’ are subject to the demands of the Constitution which defines powers and . . . sets out . . . how those powers are to be exercised.” INS v. Chadha, 462 U. S. 919, 945 (1983). Even in the face of a perceived necessity, the Constitution protects us from ourselves. New York v. United States, 505 U. S. 144, 187–188 (1992).

In the end, Justices Scalia, Thomas, and Alito seem like sure votes to overturn Seminole Rock in the appropriate case.

Update: In what appears to be a companion opinion, Justice Thomas alludes to the Progressive Era in his discussion of the non-delegation doctrine:

Or perhaps we deliberately departed from the separation, bowing to the exigencies of modern Government that were so often cited in cases upholding challenged delegations of rulemaking authority.8

8 Much of the upheaval in our delegation jurisprudence occurred dur- ing the Progressive Era, a time marked by an increased faith in the technical expertise of agencies and a commensurate cynicism about principles of popular sovereignty. See Perez v. Mortgage Bankers Assn., post, at 19–20, n. 6 (THOMAS, J., concurring in judgment).