In the past decade, the Supreme Court of Pakistan (SCP) has dealt with several blasphemy cases. In many cases, the person accused of blaspheming is murdered by vigilantes. In some cases, the killers appeal their sentences on the basis that avenging blasphemy is a religious duty, immune to punishment. In this paper, I examine why courts capitulate to populist demands to spare the life of convicts in some cases, while in other cases they do not. I argue that courts reject appeals to Islam as a broad legal principle when such appeals undercut the state’s monopoly to speak authoritatively about Islam and undermine its authority to delineate the role of Islam in the constitutional system. Through an examination of two high-profile blasphemy- related cases, I demonstrate that the SCP has effectively nullified recent attempts to invoke religious legal arguments. In doing so, I argue that the SCP has advanced a new narrative about the limits of Islamic provisions of Pakistan’s constitution.