In products liability cases involving prescription medicines, defendants sometimes rely on a preemption defense that FDA would not have approved – or in some cases, already rejected – the warnings that plaintiffs argue were required by state law. Where the evidence shows FDA considered and rejected plaintiffs’ proposed warnings, plaintiffs often argue that the Agency would have approved their proposed warnings were it not for some technical issue. For example, that FDA rejected the warning because the manufacturer asked to put it in the wrong section of the label or FDA would have approved it had the manufacturer asked rather than some third party in a Citizen’s Petition. In rejecting such arguments courts often point, explicitly or implicitly, to the presumption of regularity, which “presumes” government agencies have “properly discharged their official duties” unless “clear evidence” shows otherwise. See United States v. Chem. Found., Inc., 272 U.S. 1, 14-15 (1926); see also Nat’l Archives & Recs Admin. v. Favish, 541 U.S. 157, 174 (2004) (requiring “meaningful evidentiary showing” to rebut presumption of regularity).