In the United States v. Ptasynski et al., 1982, the Supreme Court ruled on a case involving an exemption from a federal tax for Alaskan oil. The plaintiffs argued that this was discriminatory and violated the Uniformity Clause of the Constitution, which requires taxes to be uniform across all states. However, Congress had justified it by stating that Alaska's unique geographical and environmental conditions made oil production more costly there than in other parts of the country. The court held that while taxes must be geographically uniform, they do not have to be absolutely equal in every instance; differences can exist if they are based on relevant factual differences between classes or locations being taxed differently. Therefore, it upheld Congress' power to create such exemptions when warranted by specific circumstances and found no violation of constitutional principles.

The dissenting opinion in the United States v. Ptasynski case argued that the Alaskan exception to a federal tax on crude oil was unconstitutional because it violated the Uniformity Clause of the Constitution, which requires all duties, imposts and excises to be uniform throughout the United States. The dissenters believed that Congress had no authority to create geographical exceptions for taxes based solely on regional economic considerations or policy preferences. They contended that such an approach would allow Congress to favor certain regions over others arbitrarily, undermining national unity and fairness in taxation. Furthermore, they disagreed with majority's interpretation of "uniformity," arguing instead for a stricter understanding where any geographic discrimination is deemed unconstitutional unless justified by clear necessity.