I understand the point that Stephan has been making on Kelo, but I disagree in one key area: Stephan believes that the case was correctly decided on the basis of federalism, and even has said that even though SCOTUS did not make a direct appeal to federalism to decide the case, that was OK, since the court made the "right" decision.
I have a problem with that. The court upheld the city of New London because it said that the city used a "formula" to determine if there was a projected benefit that justified the seizing of private property to sell to other private entities. There was no direct appeal to federalism, and, as we already know, the Supreme Court does not care a whit about the limits of federalism. It will appeal to federalism on a piecemeal basis, not as a matter of legal principle.
I, for one, care as to the legal reasoning the court uses to reach a decision. I want to know if the court respects principles of federalism and the institution of private property. From what I could tell with the Kelo decision, the court respected neither. All the court did in this case was to say that as long as a political entity uses a "proper" cost-benefit analysis, then it can take all of the private property it wants for whatever reason it wants.
Now, if the court had appealed first and foremost to the principles of federalism in Kelo, and were being consistent in upholding this principle, then I would be willing to defend its actions. However, the court instead appealed to bad economics. In the end, what we have is SCOTUS placing its stamp of approval upon even more government theft without leaving us any hope that it will respect federalist principles in the future. Yes, legal reasoning matters, and it matters greatly.