Not interest groups themselves, but laws that only serve as interest group protection. My theory of natural law argues that reason is the only justifiable restriction on freedom. These reasons create moral principles and those moral principles applied to social facts create just laws. To the extent laws are arbitrary, they are unjust laws.

The example I provide is the trade restriction in Williamson v. Lee Optical. Basically, since courts have recognized rights in the social sphere (as shown by equal protection and substantive due process rulings) similar rights should be recognized in the economic sphere to strike down laws that lack a rational basis.