Actually, the more likely point is that a libertarian could think that Kelo was rightly decided because it shouldn't have been a federal issue. As much as my sympathies run in the other direction, I find it hard to logically dispute this point; if you take federalism seriously, you have to take all of it, and incorporation (enforcing the Bill of Rights against the states) is a pretty obvious encroachment on state authority. State eminent domain belongs in state courts regarding state law--where the citizens of that state can threaten to oust their entire legislature come November if the law isn't fixed.