Preemption, of course, can be a valuable defense in pharmaceutical and medical device product liability cases. The presumption against preemption originated in “field” preemption cases. In a sentence, field preemption is the total exclusion of state regulation from a particular “field” by the nature or comprehensiveness of the federal assertion of responsibility. From there, it’s been imported into express preemption cases as sort of a canon of statutory interpretation. With one arguable exception, the presumption against preemption hasn’t been employed – by the Supreme Court, anyway – to take the edge off actual conflicts between federal and state law. That’s not to say that the Court might not extend the presumption to every form of preemption, only that it has yet to do so, and that there are good reasons for not doing so.
Foremost among the recent cases applying the presumption is Medtronic, Inc. v. Lohr, 518 U.S. 470 (1996), an express preemption case involving medical devices. In Lohr, the presumption was used as a narrowing principle of statutory construction: “[W]e use[] a presumption against the pre-emption of state police power regulations to support a narrow interpretation of such an express command.” Id. at 485 (plurality). In the express preemption context, the presumption was viewed as “consistent with both federalism concerns and the historic primacy of state regulation of matters of health and safety.” Id. Significantly, Justice Breyer, whose vote was necessary to create a majority in Lohr, relied upon conflict preemption principles in his concurrence. Id. at 507-08. Consistent with that reliance, Justice Breyer did not apply a presumption against preemption in his analysis.
The presumption asserted by the Lohr plurality originated in preemption discussions involving neither express nor conflict preemption – but rather “field” preemption. Thus, in Rice v. Santa Fe Elevator Corp., 331 U.S. 230 (1947), the Court noted, “the assumption that the historic police powers of the States were not to be superseded by the Federal Act unless that was the clear and manifest purpose of Congress.” Id. at 230 (citations omitted). Rice held that a federal statute regulating certain warehouse fees did away with a previous “dual” system of regulation, and completely ousted state power. Id. at 234-35. Rice involved the most sweeping form of preemption – field, not conflict preemption.
The Rice assumption became a presumption in Hillsborough County v. Automated Medical Laboratories, Inc., 471 U.S. 707, 715-18 (1985), and Jones v. Rath Packing Co., 430 U.S. 519, 525 (1977) (cases also cited in Lohr). Both of these cases rejected field preemption before turning to additional preemption arguments raising actual conflicts with federal regulation. Both courts invoked a “presumption” against preemption solely in their discussions of field preemption. Neither Hillsborough (an FDCA case) nor Jones referred to any “assumption” or “presumption” as somehow minimizing claimed conflicts between federal and state law. See 471 U.S. at 719-22 (finding no conflict preemption); 430 U.S. at 431-43 (finding conflict preemption). Far from being authority for extending a presumption against preemption to conflict preemption, if anything Hillsborough and Jones stand for the opposite proposition.
Lohr also relied (518 U.S. at 484-86) upon Cipollone v. Liggett Group, Inc., 505 U.S. 504 (1992), which more than any other case converted the original Rice/Jones presumption against field preemption into a rule of construction for express preemption clauses. See 505 U.S. at 518 (“[W]e must construe these provisions in light of the presumption against the pre-emption of state police power regulations. This presumption reinforces the appropriateness of a narrow reading.”). As in Lohr itself, there was no implied conflict preemption issue in Cipollone (the pre-emptive scope. . .is governed entirely by the express language,” 505 U.S. at 517).
The Court also raised the presumption against preemption in Buckman Co. v. Plaintiffs’ Legal Committee, 531 U.S. 341 (2001), an FDCA implied preemption case. It did so solely to hold that the presumption was inapplicable in the first instance, since its fundamental premise – a field traditionally occupied by the states – did not exist:

Policing fraud against federal agencies is hardly “a field which the States have traditionally occupied,” such as to warrant a presumption against finding federal pre-emption of a state-law cause of action. To the contrary, the relationship between a federal agency and the entity it regulates is inherently federal in character.

Id. at 347 (citation to Rice omitted). Buckman is certainly not precedent for applying the presumption against presumption to a case of actual state-federal conflict.
The application of the presumption against preemption in Geier v. American Honda Motor Co., 529 U.S. 861 (2000), is also noteworthy. Geier was a hybrid express and implied preemption case involving product liability design defect claims. Express preemption failed because the statute had conflicting preemption and savings (anti-preemption) clauses that effectively cancelled each other out. Id. at 867-68. The demise of express preemption, however, did not affect implied preemption at all. Id. at 870. Rather the two clauses combined to create “neutral” ground upon which “ordinary” preemption principles applied:

Why, in any event, would Congress not have wanted ordinary pre-emption principles to apply where an actual conflict with a federal objective is at stake? Some such principle is needed. In its absence, state law could impose legal duties that would conflict directly with federal regulatory mandates.

Id. at 87. The Geier court thus did not mention (much less rely upon) any presumption against preemption in concluding that the tort claims in question were impliedly preempted. Id. at 882-86. The majority rejected the dissent’s position (which explicitly advocated applying the presumption against preemption to implied preemption, id. at 907-08) because the dissent “relies on cases, or portions thereof, that did not involve conflict pre-emption. And conflict pre-emption is different in that it turns on the identification of ‘actual conflict,’ and not on an express statement of pre-emptive intent.” Id. at 884 (citations, including to Hillsborough, omitted).
The analysis in Smiley v. Citibank (South Dakota), N.A., 517 U.S. 735 (1996), decided almost contemporaneously with Lohr, also merits comment. In opposing preemption, the petitioner argued that the presumption essentially trumped deference to administrative determinations under Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984). 517 U.S. at 743-44. The Court rejected this argument because no question concerning the scope of the statute’s preemption provision was presented. Id. at 744 (“there is no doubt that [it] pre-empts state law”). Because scope of express preemption was not at issue, the case “d[id] not bring into play the considerations [the presumption against preemption] petitioner raises.” Id.
Doubts about the validity of a presumption against preemption in implied preemption cases are further heightened by the lack of any discussion of such a presumption in so many of the Supreme Court’s landmark implied preemption decisions. This is true of cases involving preemption of state tort suits. See International Paper Co. v. Ouellette, 479 U.S. 481 (1987) (no presumption raised to resist preemption of state nuisance law); Chicago & Northwest. Transportation Co. v. Kalo Brick & Tile Co., 450 U.S. 311 (1981) (same with respect to state negligence law). The same lack of any presumption analysis is also found in major conflict preemption cases involving state statutes or regulations. See, e.g., City of New York v. F.C.C., 486 U.S. 57 (1988); Fidelity Federal Savings & Loan Ass’n v. de la Cuesta, 458 U.S. 141 (1982); Florida Lime & Avocado Growers, Inc. v. Paul, 373 U.S. 132 (1963).
The presumption against preemption is not even applied in all express preemption cases. In one recent decision, Engine Manufacturers Ass’n v. South Coast Air Quality Management District, 541 U.S. 246 (2004), the majority found preemption on the basis of “categorical” statutory language, and expressly declined to apply any presumption against preemption. Id. at 256.
Other Supreme Court cases invoking the presumption against preemption likewise have not applied it to implied preemption situations. These cases:

• Like Lohr involve interpretation of the scope of express preemption clauses. Bates v. Dow Agrosciences LLC, 544 U.S. 431, 432-33 (2005); Egelhoff v. Egelhoff, 532 U.S. 141, 515-52 (2001); De Buono v. NYSA-ILA Medical & Clinical Services Fund, 520 U.S. 806, 813 (1997); New York State Conference of Blue Cross & Blue Shield Plans v. Travelers Insurance Co., 514 U.S. 645, 654-55 (1995); California Div. of Labor Standards Enforcement v. Dillingham Construction, 519 U.S. 316, 325 (1997); CSX Transportation, Inc. v. Easterwood, 507 U.S. 658, 668 (1993); Morales v. Trans World Airlines, Inc., 504 U.S. 374, 419-21 (1992); FMC Corp. v. Holliday, 498 U.S. 52, 62 (1990); Metropolitan Life Insurance Co. v. Massachusetts, 471 U.S. 724, 741 (1985). Cf. Pharmaceutical Research and Manufacturers v. Walsh, 538 U.S. 644, 664 (2003) (applying presumption against preemption to interpretation of scope of savings clause); Gade v. National Solid Wastes Management Ass’n, 505 U.S. 88, 98 (1992) (same).
• Like Buckman involve fields not traditionally occupied by the states. Merrill Lynch, Pierce, Fenner & Smith, Inc. v. Dabit, 126 S. Ct. 1503, 1514-15 (2006); United States v. Locke, 529 U.S. 89, 108-09 (2000).
• Involved the scope of Congress’ underlying delegation of preemptive power, to which no presumptions apply. New York v. F.E.R.C., 535 U.S. 1, 19-20 (2002).

In the only case in which the presumption seems to have been invoked in a pure conflict preemption case, it did not play any ascertainable part in the ultimate holding. See California v. ARC America Corp., 490 U.S. 93, 101 (1989) (mentioning presumption as something to “overcome”). ARC was an antitrust case, and the Court held that decisions interpreting federal antitrust statutes did not purport to “defin[e] the interrelationship between the federal and state antitrust laws.” Id. at 105. With neither preemptive intent nor any actual conflict in evidence, there was thus no basis for preemption of any sort. In the end there was nothing for the presumption to “overcome” – undoubtedly why it was not invoked when the Court actually analyzed the respondent’s substantive preemption arguments. Id. at 102-06.
Beyond the ARC case, the only other Supreme Court basis for applying the presumption against preemption in implied conflict preemption cases is erroneous dictum in F.E.R.C., a case that ultimately “d[id] not involve a ‘presumption against pre-emption’” at all. 535 U.S. at 18. F.E.R.C. described the inapplicable presumption as “most often stated. . .when a controversy concerned not the scope of the Federal Government’s authority to displace state action, but rather whether a given state authority conflicts with, and thus has been displaced by, the existence of Federal Government authority.” Id. The three cases it cited, however, were Hillsborough, which applied the presumption only as to field preemption, and not as to implied preemption; Lohr, solely an express preemption case; and Cipollone, also exclusively involving express preemption. Ironically, F.E.R.C. did not even cite ARC, the one case that arguably could have supported the Court’s dictum.
Moreover, there are sound doctrinal reasons why application of a presumption against preemption isn’t appropriate in cases of actual conflict – beyond it being virtually unprecedented. Black letter constitutional law holds that the Supremacy Clause preempts any state law conflicting with the exercise of federal power. E.g., Fidelity Federal Savings & Loan Ass’n v. de la Cuesta, 458 U.S. 141, 153 (1982) (“state law is nullified to the extent that it actually conflicts with federal law”). The importance of the state law is immaterial. “The relative importance to the State of its own law is not material when there is a conflict with a valid federal law, for the Framers of our Constitution provided that the federal law must prevail.” Id. (citation and quotation marks omitted). Conflict preemption thus starts and ends with the principle that federal law is supreme: “This principle was made clear by Chief Justice Marshall when he stated for the Court that any state law, however clearly within a State’s acknowledged power, which interferes with or is contrary to federal law, must yield.” Free v. Bland, 369 U.S. 663, 666 (1962) (citing Gibbons v. Ogden, 22 U.S. 1 (1824)). Once a federal-state conflict is established, preemption is “inescapable and requires no inquiry into congressional design.” Florida Lime & Avocado Growers, Inc. v. Paul, 373 U.S. 132, 142-43 (1963).
Because conflict-preemption rests upon a finding of conflict, rather than in any express statement of congressional intent to preempt, conflict preemption analysis necessarily focuses on the existence of a conflict, rather than on congressional intent. “[A] narrow focus on Congress’ intent to supersede state law is misdirected, for a pre-emptive regulation’s force does not depend on express congressional authorization to displace state law.” City of New York v. FCC, 486 U.S. 57, 64 (1988). This “correct focus” requires only determining that any particular federal action is statutorily authorized. Id. If the exercise of federal power is legitimate, then any conflict is preemptive. Id. Accord Brown v. Hotel & Restaurant Employees & Bartenders International Union Local 54, 468 U.S. 491, 501 (1984) (“[e]ven in the absence of such express language or implied congressional intent to occupy the field, we may nevertheless find state law to be displaced to the extent that it actually conflicts with federal law”). Holding that a presumption against preemption requires something more than simply a conflict with supreme federal law in order to preempt state law would fly in the face of Supreme Court precedent dating back to Gibbons v. Ogden.