Abstract: This essay explores the policy bases for, and the political economy of, the law's long-standing regulation of corporate political speech. The essay has three parts. First, it contends that the conventional justifications for regulating corporate interventions in politics -- that corporate donations unnaturally skew the political discourse (bad politics) and that corporate political donations harm shareholders (agency costs) -- assume irrational investors and substantial capital market inefficiency. Drawing on public choice theory, the essay also explores the aim of retarding rent-seeking as an alternative justification for regulating corporate interventions in politics. Second, the essay reexamines the history of the regulation of corporate political speech and suggests a political economy analysis whereby corporations favored limitations on corporate donations in order to obtain protection from rent extraction by politicians. Finally, the essay explores the implications of this analysis for the modern regulation of corporate political donations.