Armco Inc. v. Hardesty
In Armco Inc. v. Hardesty, 467 U.S. 638 (1984), the Supreme Court invalidated the West Virginia tax scheme that had also been applied against Ashland as discriminatory against interstate commerce. In Armco, an Ohio corporation contested the applicability of West Virginia's wholesale tax on its in-state sales of steel and wire rope. In ruling that the tax violated the Commerce Clause, the Court relied on Boston Stock Exchange v. State Tax Comm'n, 429 U.S. 318, 332, n. 12 (1977), which held that a State "may not discriminate between transactions on the basis of some interstate element."
On its face, West Virginia's statutory scheme had just such a discriminatory effect, as it "provides that two companies selling tangible property at wholesale in West Virginia will be treated differently depending on whether the taxpayer conducts manufacturing in the State or out of it." Armco, supra, at 642.