Are federal prosecutions of non-federal officials for corruption likely to improve non-federal government? This essay suggests that such prosecutions can undermine the distinctive style of democracy at the state and local level, an effect that can be harmful to democracy in America overall. This conclusion rests on a larger argument about the different nature of federal and non-federal democracy in the United States. To insure that each official maintains impartial loyalty to values defined by a single, popularly accountable policymaker, the federal system of bureaucratic populism strictly separates the officials’ public and private interests, through various devices such as civil service protection for executive officials, Article III life tenure, and fixed salary for federal judges, specialized training for federal officers, and conflict-of-interest rules that bar federal officers from acting when their judgment could be compromised by private interests. By contrast, participatory populism rejects this separation of the public and private spheres, instead mixing professional and lay decision-making by using thousands of part-time, under-paid executive and legislative officers who are expected to have substantial private interests in the communities that they represent. The essay argues that each style of democracy has mutually exclusive advantages and disadvantages. However, enforcement of federal anticorruption law against non-federal democracies can undermine their system of mingled private and public interests, reducing the degree to which such governments can provide laypersons with opportunities for political activity. As an illustration of the overextension of federal criminal law, I examine the First Circuit’s interpretation of 18 U.S.C. §§ 1341 and 1346, the federal mail fraud statute in United States v. Sawyer. Sawyer comes dangerously close to declaring that any undisclosed state or local officer’s conflict of interest constitutes a violation of § 1346 when it involves the U.S. mails. I argue that this view of § 1346 is an error. Participatory populism requires that private and public tasks be closely mingled in ways that bureaucratic populism forbids. Undoubtedly, this mixture of public and private creates a risk that public office will be used for private gain. However, it also avoids some of the bureaucratic sclerosis and lack of lay participation that can be endemic to the more centralized federal tradition. In conclusion, I suggest that federal prosecutors ought to content themselves with using § 1346 to enforce already-existing state criminal conflict-of-interest rules, for the sake of preserving a place in our federal regime for participatory populism.