In the case of Wolman et al. v. Walter et al., 1976, the U.S. Supreme Court ruled on a challenge to an Ohio law that provided financial assistance to nonpublic schools, including parochial ones. The court held that certain forms of aid were constitutional while others were not. Specifically, it found that providing textbooks and standardized testing services did not violate the Establishment Clause as they had secular purposes and their primary effect neither advanced nor inhibited religion. However, other provisions such as funding for field trips or remedial education taught by public employees in religious schools were deemed unconstitutional due to excessive entanglement between church and state or potential indoctrination risks respectively. The decision was split with no clear majority opinion; instead there was a plurality opinion (an opinion agreed upon by less than half but more than any dissenting group), concurring opinions (agreement with result but different reasoning) and dissents (disagreements). This complexity reflected ongoing debates about how best to interpret First Amendment's prohibition against government establishment of religion in context of public support for private education.

In the dissenting opinion for Wolman et al. v. Walter et al., Justice William J. Brennan Jr., joined by Justices Thurgood Marshall and Potter Stewart, argued that Ohio's law providing financial aid to nonpublic schools did not violate the Establishment Clause of the First Amendment as it maintained a clear line between church and state. They contended that this aid was intended to ensure all children received quality education regardless of their school type, rather than promoting religion in any way. The justices also disagreed with the majority's view on field trips, stating there was no evidence these would be used for religious indoctrination purposes; they believed such concerns were speculative at best. Furthermore, they asserted that striking down parts of Ohio’s law could potentially harm many other states' similar programs designed to support non-public schools.