Mclaughlin v. Fowler was a United States Supreme Court case that dealt with the issue of whether a state could tax the income of a non-resident. The case was brought by a resident of New York, who was employed by a company in Pennsylvania. The company paid him wages, which were subject to a Pennsylvania income tax. The plaintiff argued that the Pennsylvania tax was unconstitutional, as it violated the Due Process Clause of the Fourteenth Amendment. The Supreme Court held that the Pennsylvania tax was constitutional, as it did not violate the Due Process Clause. The Court reasoned that the tax was not discriminatory, as it applied equally to all non-residents of Pennsylvania. Furthermore, the Court held that the tax was not an undue burden on interstate commerce, as it was not excessive or oppressive. In conclusion, the Supreme Court held that the Pennsylvania income tax was constitutional, and did not violate the Due Process Clause of the Fourteenth Amendment. The Court reasoned that the tax was not discriminatory, and did not impose an undue burden on interstate commerce.

Justice Harlan delivered the dissenting opinion in McLaughlin v. Fowler, arguing that the majority's decision was contrary to both precedent and sound public policy. He argued that a state cannot be held liable for damages caused by its officers when they are acting within their authority, even if those actions were illegal or unconstitutional. Furthermore, he asserted that it is not appropriate for courts to second-guess the decisions of state officials who are charged with carrying out their duties in good faith and without malice or corruption. Finally, Justice Harlan argued that allowing states to be sued would undermine public confidence in government institutions as well as lead to an increase in litigation against them which could have serious financial consequences for taxpayers.