108 Iowa L. Rev. 2189 (2023)
What is a substantial burden on religious exercise? This question continues to stand at the very center of religious liberty debates, animating both present interpretation of the Religious Freedom Restoration Act as well as the trajectory of future free exercise doctrine. In this Essay, I defend the view that courts should interpret the substantiality of burdens by examining the extent of government-imposed civil penalties for noncompliance. Doing so ensures courts avoid assessing the theological substantiality of burdens—inquiries that are prohibited by the Establishment Clause’s religious question doctrine. At the same time, a civil penalties approach to substantial burdens provides courts with a method for limiting religious liberty claims; that is, claimants would still have to demonstrate that the imposition of civil penalties constitutes a substantial burden and judges would have the opportunity to evaluate whether claimants had satisfied that burden. Critics have contended that the civil penalties approach to substantial burdens fails for a variety of reasons. But carefully following the underlying logic behind the approach demonstrates its ability to meet these challenges and provide courts with a meaningful and principled opportunity to evaluate claims for religious accommodations.