For the first time in nearly a century, the conservative scholars, judges, lawyers, and advocacy groups challenging the constitutional foundations of the modern administrative state have reached a critical mass. However, by relying on originalist foundations, these critics may be inviting in a Trojan Horse. As I argue in a forthcoming article, returning to 19th century administrative law would smuggle in an unwelcome consequence: largely eliminating judicial review of the constitutionality of agency action. As a result, they may have to choose between their originalist attack on the modern administrative state and preserving a type of court review they value highly.