Barnetts analysis shows that the courts begin with the assumption that federal laws are constitutional. This places the burden on plaintiffs to prove unconstitutionality. Given 70+ years of awful case law, it is a high hurdle.
By the Ninth Amendments presumption of liberty, Barnett shows how the burden should be on the government to prove that law is necessary and proper to execute an enumerated power that does not infringe on our natural or enumerated rights.
Thanks for the ping!