Joseph P. Bradley, Clinkenbeard v. United States…
“ But if they assess persons, property, or operations not taxable, such assessment is illegal and cannot form the basis of an action at law for the collection of the tax, however efficacious it may be for the protection of ministerial officers charged with the duty of actual collection by virtue of a regular warrant or authority therefor. When the government elects to resort to the aid of the courts it must abide by the legality of the tax. ”
