The U.S. Supreme Court case Fiallo v. Bell, 1976, revolved around the constitutionality of sections of the Immigration and Nationality Act that provided special preferences for immigration visas to parents of U.S citizens or permanent residents but excluded fathers and their illegitimate children from these benefits. The plaintiffs argued that this exclusion violated equal protection principles by discriminating based on gender and legitimacy status. However, the Supreme Court upheld the provisions in a 6-3 decision stating that Congress has broad power over immigration policy which is not subject to judicial review under normal circumstances unless it clearly violates constitutional rights - which was not found in this case. The court ruled that distinctions made by Congress related to familial relationships were permissible as they are often used as determinants in immigration law.

In the dissenting opinion for Fiallo v. Bell, Justice Thurgood Marshall argued that the majority's decision to uphold immigration laws discriminating against illegitimate children and their natural fathers was a violation of equal protection principles. He contended that these groups were being unfairly singled out based on an "illegitimacy" status they had no control over, which he believed constituted invidious discrimination. Furthermore, he criticized the majority for deferring too heavily to Congress' authority over immigration policy without adequately scrutinizing whether such discriminatory policies served any legitimate governmental interest. In his view, this deference allowed Congress to enact laws infringing upon fundamental rights without sufficient justification or oversight from the judiciary branch.