Mark writes: “When I served at the Justice Department, we made an effort to persuade the Court that regulatory takings were takings under the the Fifth Amendment. An enormous amount of research and historical information was compiled. I wish I had it here, but I don’t.” My point is that this historical research doesn’t help on this point. I agree with Mark that regulatory takings are “takings” requiring compensation, and that historical work supports that conclusion despite the lack of “regulatory takings” in the founding period, but that’s irrelevant here. Rather the question is about what government can do in the first place, not whether compensation is due.

Justice Thomas marshalls just about all of the historical evidence that is available for his position, but it’s not enough to carry the day. Thomas’s attempts to distinguish Mill Acts and Private Road Acts — both of which are strong evidence of how the founders viewed the power of eminent domain — are unpersuasive. Others who’ve done the historical research come to the same unfortunate conclusion: The originalist case for a robust “public use” requirement is fairly weak. I’d like to be persuaded otherwise, and would welcome further academic research that supports the Thomas position. As yet, I haven’t seen it.