Which countries are most common for dual citizens in the U.S. Congress?
Executive summary
Current reporting does not provide a definitive ranked list of which foreign countries are most common among dual‑citizen members of the U.S. Congress; available coverage notes that “a surprising number” of members hold foreign ties and names specific examples (e.g., Tammy Duckworth—Thailand; Victoria Spartz—Ukraine) but stops short of comprehensive counts [1]. Recent legislative activity—House proposals to require disclosure and a Senate bill to ban dual citizenship—has driven renewed attention to the issue but not to precise country-by-country frequencies [2] [3].
1. Why the question matters now: lawmakers pushing disclosure and bans
Republican lawmakers in 2025 have proposed measures that would force members of Congress to disclose foreign citizenship or bar dual citizens from serving, and Senator Bernie Moreno has introduced the Exclusive Citizenship Act of 2025 aimed at eliminating dual nationality for all Americans—moves that put the foreign origins and secondary nationalities of public officials squarely in the spotlight [2] [3]. Those proposals have prompted media stories pointing out specific members with foreign ties, which fuels public interest in which countries crop up most often among legislators [2] [1].
2. What reporters actually say about Congress members’ secondary nationalities
News and commentary pieces note individual examples and counts of foreign‑born lawmakers rather than a systematic tally of dual citizenship by country. A travel blog and related reporting say “a surprising number” of members have dual citizenship and list examples—Tammy Duckworth (U.S.–Thailand) and Victoria Spartz (born in Ukraine)—and cite figures about foreign‑born members and governors, but they do not offer a ranked breakdown of countries of second citizenship [1]. National outlets covering the Moreno bill likewise mention possible affected people and estimates of dual nationals in the U.S. population, but they do not supply an authoritative country‑by‑country list for Congress [3].
3. Why there is no authoritative country ranking in these sources
Available sources explain practical and data limitations: the U.S. government and most other countries do not maintain comprehensive public statistics on who holds dual nationality, so “no one knows just how many citizens claim a second nationality” and journalists rely on public disclosures and reporting rather than central records [4]. That absence of central data makes compiling a reliable list of “most common foreign citizenships among Congress members” impossible from current reporting [4].
4. What partial evidence the articles do provide
Reporting highlights notable individual cases and estimates of the broader pool of dual nationals in the U.S.: some articles point to named members with foreign ties (examples above) and cite wide estimates of dual‑citizen Americans ranging from hundreds of thousands to several million, which contextualizes why politicians are targeting dual citizenship even though precise congressional counts aren’t presented [1] [3]. Several stories also underscore legal and constitutional stakes—how renunciation requirements would clash with Supreme Court precedent—rather than producing granular demographic lists [3] [4].
5. Competing viewpoints and hidden agendas in the coverage
Proponents frame restrictions as protecting national allegiance and preventing conflicts of interest; the Moreno bill expressly argues for “sole and exclusive allegiance” and would require dual nationals to choose within a year or risk losing U.S. citizenship [3]. Critics and some legal analysts warn the proposals conflict with precedent (Afroyim v. Rusk) and practical realities—some countries won’t accept renunciations—casting the bills as politically motivated extensions of broader immigration and citizenship attacks [4] [5]. Media outlets vary in tone: some emphasize national‑security framing from sponsors, while others highlight constitutional vulnerability and practical implausibility [2] [5].
6. Bottom line and next steps for anyone seeking a country ranking
Current reporting does not supply the country‑level ranking you asked for; to produce one would require primary data the articles say do not exist publicly—either official disclosure forms for all members or a vetted database of individual citizenships [4]. If you want a reliable list, the next step is a dedicated audit: gather each member’s oath/biography, public disclosures, and media reporting, then verify foreign‑national status with primary documents—something journalists and watchdogs would need to undertake and the current articles have not done [1] [4].