In Wyeth v. Levine, the United States Supreme Court revitalized the sometimes dormant “presumption against pre-emption” by declaring it one of two cornerstones of preemption jurisprudence. Under the presumption, the analysis of a claim that federal law preempts state law starts with “‘the assumption that the historic police powers of the States were not to be superseded by the Federal Act unless that was the clear and manifest purpose of Congress.”’ Although the Court previously had instructed lower courts that the preemption analysis always begins with a “basic presumption against pre-emption,” the Court itself often has honored that mandate in the breach--when it has bothered to mention the presumption at all.. . .