Cass Sunstein and Richard Thaler (2003, 2006, 2009) contend that the government is justified in shaping certain choices of individuals to advance their well-being. In this paper, I argue that those who are committed to a robust notion of autonomy, which I call autonomy as authority, have good reason to reject the Sunstein-Thaler (S/T) argument for libertarian paternalism. I draw from Joseph Raz's (1990) idea of exclusionary reasons and Daniel Groll's (2012) conception of autonomy to argue that the S/T argument for libertarian paternalism fails to respect autonomy. I consider if soft paternalism could be called upon as a foundation for libertarian paternalism, but argue against this possibility. I conclude that an adequate defense of libertarian paternalism would need to directly attack the notion of autonomy as authority, but such an attack has yet to be mounted by the defenders of libertarian paternalism.