In the 1937 case Hale et al. v. State Board of Assessment and Review, the U.S Supreme Court ruled on a dispute involving taxation policy in Iowa. The plaintiffs, who were shareholders in an investment trust, argued that they were being unfairly taxed by the state's board of assessment and review because their shares were being valued at full market price while other types of property (like real estate) were assessed at only a fraction of their actual value. They claimed this discrepancy violated the Equal Protection Clause of the Fourteenth Amendment to the Constitution which guarantees all citizens equal protection under law. The court disagreed with them, ruling that it was within states' rights to tax different forms of property differently as long as there was no clear discrimination or violation against any particular group or class under those laws. This decision upheld Iowa’s right to use its own discretion when determining how various types properties are taxed.

In the dissenting opinion for Hale et al. v. State Board of Assessment and Review, Justice Stone argued that the majority's decision was inconsistent with previous rulings regarding tax exemptions for religious institutions. He contended that the Court had previously held such exemptions to be constitutional because they served a public purpose by promoting moral or mental improvement among citizens. However, in this case, he believed that the Court failed to recognize how these same principles applied to educational institutions like Princeton University which also serve a public purpose through their contributions to education and research. Furthermore, he disagreed with the majority's interpretation of "public use," arguing it should not be limited only to government-owned property but should include any institution serving a significant public interest or benefitting society at large.