The Wages of Resting Fundamental Rights on the Commerce Clause
Starting with the labor movement of the 1900s through the 1930s and continuing through the civil rights and women's rights movements of the 1940s through the 1970s, twentieth-century social movements demanded and gained recognition for important new rights. They demanded these rights in the language and on the basis of the Reconstruction Amendments, but the Congresses that enacted the rights, the attorneys that defended the enactments, and the Courts that upheld them did so, overwhelmingly, on the basis of the commerce power. Accordingly, James Gray Pope points out in a major new study, the century's human rights movements provided a major impetus for the vast expansion of the commerce power, while the congressional powers that the movements themselves had championed -- Congress's rights-protecting powers -- remained, in Pope's words, "unrescued from nineteenth-century limitations."
The first jurisdictional compromise was the decision on the part of Senator Wagner and his staff of New Deal lawyers to rest the National Labor Relations Act (NLRA), popularly known as the Wagner Act, on the commerce power rather than on the Thirteenth or Fourteenth Amendment. By grounding the Act thus and persuading the Court in NLRB v. Jones & Laughlin Steel Corp. to do likewise, Wagner and the government attorneys enlarged the domain of legislative power and policymaking, but they left labor's hard-won rights "to the shifting outcomes of ordinary politics." Had they rested the Act instead on the Thirteenth or Fourteenth Amendment, the Court would have had to confront the constitutional rights-based arguments for the labor rights that the Act protected, thereby restraining future Congresses and Courts from diminishing and balancing away those rights so freely. The upshot also might have been a great enlargement of Congress's constitutional rights-protecting authority, beyond its nineteenth-century limitations, and consequently a greater likelihood that the broad antidiscrimination statutes of the 1960s could have rested comfortably on the Reconstruction Amendments.
So, even before the conservative counterrevolution thwarted their efforts, the New Dealers seem to have decided against constitutionalizing the new rights they championed. Pope condemns this choice, contending that the Thirteenth Amendment was the proper basis for the freedoms labor sought and the basis labor preferred. The New Deal lawyers and lawmakers chose to rest the Wagner Act on the Commerce Clause, in his view, because their professional interests were not "those of the people." They wanted to expand the constitutional power of government policymakers, experts, and social engineers, not the rights of workers…
The progressive tradition -- was Janus-faced. Progressives spoke of gaining social control over economic institutions and market relations. But "social control" was deeply ambiguous. The term could mean social and economic citizenship and democratic control: democratic, not juridical, construction of the ground rules of economic life and democratization of workplaces and other "private" institutions through unions and other forms of association. Or social control could mean what Pope highlights: control by public and private experts, social engineers, scientific managers, and policymakers… Common to both was the conviction that rights should be understood in terms of social context and social policy, redeemed and defended through legislative deliberation and enactment, and kept out of the hands of legalists and formalists.
-- WILLIAM E. FORBATH , THE NEW DEAL CONSTITUTION IN EXILE
https://www.law.duke.edu/journals/dlj/articles/dlj51p165.htm#H2N1