Justice Thomas on implied preemption in Williamson v. Mazda Motor of America, Inc.
To answer that question, the majority engages in a“freewheeling, extratextual, and broad evaluatio[n] of the ‘purposes and objectives’” of FMVSS 208. Wyeth, supra, at ___ (slip op., at 23) (opinion of THOMAS, J.). The Court wades into a sea of agency musings and Government litigating positions and fishes for what the agency may have been thinking 20 years ago when it drafted the rele-vant provision. After scrutinizing the 1989 Federal Regis-ter, a letter written in 1994, and the Solicitor General’s present-day assurances, the Court finds that Departmentof Transportation liked the idea of lap-and-shoulder seat-belts in all seats, but did not require them, primarily for cost-efficiency reasons and also because of some concernfor ingress-egress around the belt mounts. Ante, at 8–11. From all of this, the majority determines that although the regulators specifically and intentionally gave manu-facturers a choice between types of seatbelts, that choicewas not a “significant regulatory objective” and so does not pre-empt state tort lawsuits.
“[F]reeranging speculation about what the purposes of the [regulation] must have been” is not constitutionallyproper in any case. Wyeth, supra, at ___ (slip op., at 15) (opinion of THOMAS, J.). The Supremacy Clause com-mands that the “[l]aws of the United States,” not theunenacted hopes and dreams of the Department of Trans-portation, “shall be the supreme Law of the Land.” U. S. Const., Art. VI, cl. 2. The impropriety is even more obvi-ous here because the plain text of the Safety Act resolves this case.