The Afroyim decision opened the way for a wider acceptance of dual (or multiple) citizenship in United States law.

[4] The Bancroft Treaties—a series of agreements between the United States and other nations which had sought to limit dual citizenship following naturalization—were eventually abandoned after the Carter administration concluded that Afroyim and other Supreme Court decisions had rendered them unenforceable.

The impact of Afroyim v. Rusk was narrowed by a later case, Rogers v. Bellei (1971), in which the Court determined that the Fourteenth Amendment safeguarded citizenship only when a person was born or naturalized in the United States, and that Congress retained authority to regulate the citizenship status of a person who was born outside the United States to an American parent.

[10] After the Civil War (1861–65) and the resulting abolition of slavery in the United States, steps were taken to grant citizenship to the freed slaves.

Congress first enacted the Civil Rights Act of 1866, which included a clause declaring "all persons born in the United States and not subject to any foreign power" to be citizens.

An amendment proposed by Congress in 1810—the Titles of Nobility Amendment—would, if ratified, have provided that any citizen who accepted any "present, pension, office or emolument" from a foreign country, without the consent of Congress, would "cease to be a citizen of the United States"; however, this amendment was never ratified by a sufficient number of state legislatures and, as a result, never became a part of the Constitution.

After ruling in this case that Wong was born a U.S. citizen despite his Chinese ancestry, the Court went on to state that his birthright citizenship "[had] not been lost or taken away by anything happening since his birth.

"[29][30] Two Supreme Court decisions after Perez called into question the principle that loss of citizenship could occur even without the affected individual's intent.

[37][38] He studied at the Art Institute of Chicago, as well as the National Academy of Design in New York City, and he was commissioned to paint portraits of George Bernard Shaw, Theodore Dreiser, and Arnold Schoenberg.

[45] After losing his appeal to the Second Circuit,[46][44] Afroyim asked the Supreme Court to overrule the precedent it had established in Perez, strike down the foreign voting provision of the Nationality Act as unconstitutional, and decide that he was still a United States citizen.

[42] The official respondent (defendant) in Afroyim's case on behalf of the U.S. government was Dean Rusk,[50] the Secretary of State during the Kennedy and Johnson administrations (1961–1969).

[51] The oral arguments in the case were presented by attorneys Edward Ennis—chairman of the American Civil Liberties Union (ACLU)—for Afroyim, and Charles Gordon—general counsel for the INS—for the government.

[55][56][57] The court's majority now held that "Congress has no power under the Constitution to divest a person of his United States citizenship absent his voluntary renunciation thereof.

We hold that the Fourteenth Amendment was designed to, and does, protect every citizen of this Nation against a congressional forcible destruction of his citizenship, whatever his creed, color, or race.

[67]The minority—in a dissent written by Associate Justice John Marshall Harlan II and joined by Associate Justices Tom C. Clark, Potter Stewart, and Byron White—argued that Perez had been correctly decided,[68] that nothing in the Constitution deprived Congress of the power to revoke a person's citizenship for good cause,[69][70] and that Congress was within its rights to decide that allowing Americans to vote in foreign elections ran contrary to the foreign policy interests of the nation and ought to result in loss of citizenship.

[71] Harlan wrote: First, the Court fails almost entirely to dispute the reasoning in Perez; it is essentially content with the conclusory and quite unsubstantiated assertion that Congress is without "any general power, express or implied," to expatriate a citizen "without his assent."

Next, the Court embarks upon a lengthy, albeit incomplete, survey of the historical background of the congressional power at stake here, and yet, at the end, concedes that the history is susceptible of "conflicting inferences."

Finally, the Court declares that its result is bottomed upon the "language and the purpose" of the Citizenship Clause of the Fourteenth Amendment; in explanation, the Court offers only the terms of the clause itself, the contention that any other result would be "completely incongruous," and the essentially arcane observation that the "citizenry is the country and the country is its citizenry."

[89] As explained by Peter J. Spiro, "In the long run, Afroyim's vision of an absolute right to retain citizenship has been largely, if quietly, vindicated.

"[5] While acknowledging that "American citizenship enjoys strong protection against loss under Afroyim and Terrazas", retired journalist Henry S. Matteo[90] suggested, "It would have been more equitable ... had the Supreme Court relied on the Eighth Amendment, which adds a moral tone as well as a firmer constitutional basis, than the Fourteenth."

Matteo also said, "Under Afroyim there is a lack of balance between rights and protections on one hand, and obligations and responsibilities on the other, all four elements of which have been an integral part of the concept of citizenship, as history shows.

"[91] Political scientist P. Allan Dionisopoulos wrote that "it is doubtful that any [Supreme Court decision] created a more complex problem for the United States than Afroyim v. Rusk", a decision which he believed had "since become a source of embarrassment for the United States in its relationships with the Arab world" because of the way it facilitated dual U.S.–Israeli citizenship and participation by Americans in Israel's armed forces.