Final answer:
The rule of hypodescent does not apply to the determination of U.S. citizenship today. A person with a Seminole grandmother and European parents would not be denied U.S. citizenship based on ancestry. Citizenship is determined by birthright and parental citizenship, not by archaic racial classification laws.
Step-by-step explanation:
The rule of hypodescent, commonly referred to as the one-drop rule, was applied throughout much of the United States in the 20th century. Under this rule, individuals with any minority race ancestry were often deemed to be members of that minority group, regardless of their physical appearance or how they identified themselves. However, today, citizenship in the United States is determined by birthright (jus soli) and by the principle of 'jus sanguinis' or 'law of the blood,' which means a person can inherit citizenship from their parents. The landmark Supreme Court case of United States v. Wong Kim Ark established that the government cannot deny citizenship to anyone born within the United States. Therefore, a person with a maternal grandmother who is Seminole and parents of European ancestry is not denied U.S. citizenship on the basis of ancestry or the application of the historically discriminatory hypodescent rule.
Many states used variations of the one-drop rule to enforce Jim Crow laws, including the prohibition of interracial marriage and strict racial classification. Over time, and particularly in the late 1960s, the Supreme Court struck down such laws, including the ending of segregation in the U.S. military. Today, racial purity concepts and strict blood quantum rules are considered antiquated and discriminatory. In 2000, the census allowed people of mixed heritage to identify by more than a single racial category, acknowledging the complexity and diversity of American identities.
Tribal nations today manage their own membership laws, with each tribe setting its own criteria, which may include blood quantum rules for membership. However, this is separate from U.S. citizenship and does not affect a person's status as a U.S. citizen.