What do the Supreme Court precedents Afroyim v. Rusk and Vance v. Terrazas say about Congress's power to revoke citizenship?

1. Afroyim v. Rusk: citizenship is not for Congress to take away

In Afroyim the Supreme Court held that under the Citizenship Clause of the Fourteenth Amendment a citizen cannot be deprived of citizenship unless he voluntarily renounces it, reversing earlier cases that had allowed congressional expatriation by statute; the Court rejected the argument that Congress could condition citizenship on refraining from certain foreign acts such as voting abroad ^{[1] [2]}. The decision explicitly curtailed Congress’s previously broad expatriation authority and pushed U.S. law toward treating citizenship as “permanent and secure,” a ruling that opened the door to modern acceptance of dual nationality ^{[5] [6]}.

2. The government’s foreign‑affairs rationale and what Afroyim overturned

Before Afroyim, the Court in Perez v. Brownell had sustained Congressional power to cause loss of citizenship as an incident of regulating foreign affairs; Afroyim repudiated that reasoning, holding that neither the Fourteenth Amendment nor any other constitutional provision grants Congress a general power to strip acquired citizenship without assent ^{[7] [2]}. The State had argued that voting in a foreign election could be treated as an expatriating act tied to foreign‑affairs regulation, but Afroyim rejected that justification as incompatible with the Citizenship Clause ^[2].

3. Vance v. Terrazas: intent matters, but standards remain contested

Terrazas narrowed the practical effect of Afroyim by demanding proof of the individual's intent to relinquish U.S. citizenship rather than inferring that intent automatically from a statutorily defined expatriating act; the Court held that proof of intent is required and emphasized that Afroyim protects the need for assent ^{[3] [4]}. The justices, however, were divided over the burden of proof: while all agreed intention is constitutionally required, some opinions—most notably Justice Stevens’s concurrence—favored a “clear and convincing” standard, leaving lower‑court practice and administrative adjudication in a zone of uncertainty ^{[4] [3]}.

4. Practical effect: strong protection with procedural gaps

Together Afroyim and Terrazas established that Congress cannot unilaterally revoke citizenship simply by listing certain acts as expatriating; instead, loss requires evidence the person intended to abandon citizenship—therefore U.S. citizenship enjoys robust constitutional protection ^{[5] [3]}. Yet the government continued to bring denationalization cases and agencies and courts wrestled with how to prove intent and what evidentiary standard applies; legal commentators and lower courts have debated whether Afroyim forbids inferring assent from conduct entirely or merely heightens the proof required ^{[8] [9] [10]}.

5. Competing narratives and implicit institutional motives

The rulings reflect competing institutional agendas: the State and Congress had historically framed expatriation as a tool of foreign‑policy management, an approach courts once endorsed ^{[2] [7]}, whereas Afroyim and Terrazas reasserted individual constitutional protections against state power—an outcome praised by civil‑liberties advocates and criticized by those who view dual nationality or expatriation as a potential foreign‑policy problem ^{[6] [8]}. Reporting and scholarship reveal an unresolved tension between protecting citizenship as a civil right and allowing governmental regulation of international affiliations, with Terrazas leaving room for future contests over how convincingly intent must be established ^{[4] [10]}.