In the case of ASARCO Inc. v. Idaho State Tax Commission, 1981, the U.S Supreme Court ruled in favor of Idaho's method for taxing mines and mining equipment owned by out-of-state corporations. The court held that a state could tax an out-of-state corporation on its property within the state without violating due process or interstate commerce clauses if it used a formula reasonably related to values connected with the state. ASARCO Inc., an Arizona-based company operating silver and lead-zinc mines in Idaho, argued that this taxation was unconstitutional as it taxed them more heavily than other businesses because their business required large investments in land and equipment while generating relatively small profits compared to other industries such as retailing or manufacturing.

In the dissenting opinion for ASARCO INC. v. IDAHO STATE TAX COMMISSION, Justice Blackmun argued that Idaho's tax did not violate the Commerce Clause of the Constitution because it was applied to an activity with a substantial nexus within the state and fairly related to services provided by Idaho. He emphasized that Asarco’s mining and processing activities in Idaho were significant enough to establish this connection, thus justifying taxation by the state. Furthermore, he contended that there was no discrimination against interstate commerce as all businesses operating in-state were subject to similar taxes regardless of whether they sold their products intrastate or interstate. Lastly, he disagreed with majority's interpretation of Complete Auto Transit Inc., v Brady case which led them conclude that Asarco’s tax burden was disproportionate; instead asserting it should be viewed from a broader perspective considering overall fairness rather than focusing on specific aspects alone.