McDonald v. Chicago: Institute for Justice Brief

The Institute for Justice has submitted an amicus curiae brief [pdf] in support of petitioners.  Their thrust of their brief is that the 14th Amendment was meant to give teeth to the antislavery protections of the 13th, and that the marginalization of the 14th allowed "constructive servitude" to exist.  They ask that the Court look at the whole intent of the Privileges or Immunities clause, and not simply use it only as a mechanism for incorporation:

There is ample historical evidence that the purpose of the Fourteenth Amendment, and particularly the Privileges or Immunities Clause, was not merely to provide for the mechanistic “incorporation” of the first eight amendments (it would have been easy enough to say so), but instead to redress a whole host of laws, practices, customs, and mores whose common purpose was to destroy the ability of newly freed slaves to become self-sufficient members of society.  p. 12

They argue that incorporation is not only unneccesary but disingenuous, since the 14th Amendment (particularly Privileges or Immunities) was meant to protect a "pre-existing right."  Philosophically, they're absolutely correct.