In Massachusetts v. Westcott, the U.S. Supreme Court ruled in favor of Massachusetts, upholding a state law that required boats fishing within its waters to have a majority of crew members who were residents of the state. The case was brought by non-resident fishermen who argued that this requirement violated their rights under the Privileges and Immunities Clause of Article IV and the Equal Protection Clause of Fourteenth Amendment. However, the court found that there was a substantial reason for treating resident and nonresident fishermen differently due to conservation efforts as well as economic protectionism for local industries which justified any potential discrimination against out-of-state citizens.

In the dissenting opinion for Massachusetts v. Westcott, 1976, it was argued that the majority's decision to strike down a provision of the Aid to Families with Dependent Children (AFDC) program as unconstitutional was incorrect. The AFDC program provided additional benefits to families with an unemployed parent present in the home, and did not extend these benefits to households where only one parent was present but employed part-time or intermittently. The dissenting justices believed this distinction served a legitimate governmental interest by encouraging family stability and discouraging divorce or separation due to financial strain caused by unemployment. They also noted that Congress had made clear its intent for such provisions when establishing welfare programs like AFDC - namely, providing aid specifically targeted towards maintaining two-parent families during periods of involuntary unemployment. Therefore, they felt striking down this provision undermined congressional authority and overstepped judicial bounds.