The United States Supreme Court held that the Commonwealth of Kentucky's income tax scheme, which differentially taxed interest derived from bonds issued by the Commonwealth from bonds issued by other states, did not offend Dormant Commerce Clause principles and, thus, was constitutional.
Department of Revenue v. Davis, 128 S. Ct. 1801 (2008).
Gregory V. Aughenbaugh,
Differential Taxation of Interest Derived from Out-of-State Municipal Bonds Does Not Violate the Dormant Commerce Clause: Department of Revenue v. Davis,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol47/iss1/9