Heryford v. Davis was a United States Supreme Court case that addressed the issue of whether a state could tax the income of a non-resident. The case was brought by a resident of Texas, who had received income from a business in Louisiana. The state of Louisiana had imposed a tax on the income, and the plaintiff argued that the tax was unconstitutional. The Supreme Court held that the tax was constitutional, and that the state of Louisiana had the right to impose a tax on the income of a non-resident. The Court reasoned that the tax was not a burden on interstate commerce, and that the state had a legitimate interest in taxing the income of its citizens. The Court also noted that the tax was not discriminatory, as it applied equally to all non-residents. In conclusion, the Supreme Court held that the state of Louisiana had the right to impose a tax on the income of a non-resident, and that the tax was not a burden on interstate commerce. The Court also noted that the tax was not discriminatory, as it applied equally to all non-residents.

Justice Field delivered the dissenting opinion in Heryford v. Davis, arguing that a state cannot be held liable for damages caused by its officers acting outside of their authority. He argued that if states were to be held liable for such actions, it would lead to an increase in litigation and could potentially bankrupt them. Furthermore, he noted that the Constitution does not provide any basis on which a state can be sued without its consent; thus, allowing suits against states would require changing the fundamental structure of government established by the Constitution. He concluded his dissent with an argument against judicial activism: "The power assumed is too great and dangerous to remain unquestioned."