In the case of Hudson et al. v. Moonier, the United States Supreme Court ruled on a dispute involving property rights and tax obligations in 1937. The appellants, Hudson and others, were trustees of a certain railroad company who had purchased lands at sales for delinquent taxes assessed against Northern Pacific Railway Company (NP). They argued that they should not be held responsible for paying back taxes owed by NP because they were unaware of these debts when purchasing the land. However, respondent Moonier claimed that as purchasers at a tax sale, they assumed all existing liabilities associated with the property including unpaid taxes from previous owners. The court sided with Moonier stating that ignorance does not exempt one from such responsibilities under law; it is generally understood that buyers assume any encumbrances or liens upon purchase unless explicitly stated otherwise in their contract or deed. Therefore, Hudson et al., as successors to NP's title to these lands through purchase at tax sales are liable for payment of all outstanding charges regardless if they knew about them prior to acquisition.

In the dissenting opinion for Hudson et al. v. Moonier, it was argued that the majority's decision to uphold a state law requiring liquor dealers to purchase a license and pay an annual fee was unconstitutional. The dissenting justices believed this law violated the Fourteenth Amendment's Equal Protection Clause because it unfairly targeted one group of people (liquor dealers) while exempting others who were similarly situated (other types of businesses). They also disagreed with the majority's interpretation of what constituted "privilege" under state law, arguing instead that selling liquor should be considered a right rather than a privilege subject to regulation and taxation by the government. Furthermore, they contended that even if such sales could be classified as privileges, there was no rational basis for treating them differently from other commercial activities in terms of licensing requirements and fees.