Which countries are most common among U.S. lawmakers with dual citizenship?

1. The bill forcing the question: a quick frame

Sen. Bernie Moreno’s proposal would make it unlawful to be a U.S. citizen while retaining any foreign citizenship and would impose systems for declaration, verification and recordkeeping through the State Department and DHS ^{[1] [2]}. Media coverage frames the bill as part of a broader Republican push to tighten immigration and citizenship rules and to address what sponsors call “conflicts of interest and divided loyalties” among public officials ^{[2] [5]}.

2. What the press says about lawmakers with foreign ties

Several outlets cite that “a surprising number” of members of Congress hold foreign ties—examples commonly referenced in earlier debates include Rep. Tammy Duckworth’s Thai citizenship and Rep. Victoria Spartz’s Ukrainian origins—but the current collection of sources does not produce an evidence-backed list of the most frequent foreign citizenships among U.S. lawmakers ^{[4] [3]}. News coverage of the Moreno bill primarily emphasizes potential high-profile impacts (for example, Melania Trump’s Slovenian citizenship is cited) rather than statistical tabulations of lawmakers’ second nationalities ^{[6] [7]}.

3. Data gaps and why no clear “most common” country appears in coverage

Multiple sources warn that the U.S. does not maintain comprehensive statistics on dual nationals and that prior reports have estimated the total number of U.S. dual citizens variably—from hundreds of thousands to several million—making specific counts among lawmakers hard to establish from public records alone ^{[8] [7]}. A 2000 Center for Immigration Studies report is invoked in local coverage to stress the absence of reliable lists or databases ^[8]. In short: available reporting does not supply the country-by-country counts you asked for ^[8].

4. Examples journalists repeat — not a ranked list

When outlets illustrate the issue they rely on individual, high-profile examples: Tammy Duckworth (Thailand), Victoria Spartz (Ukraine), and public discussion of Melania Trump’s Slovenian passport as a potential casualty of a ban. Those examples indicate that countries tied to lawmakers often reflect birthplace or family origin rather than a uniform pattern favoring one particular foreign citizenship ^{[4] [6] [7]}.

5. Competing perspectives in the reporting

Supporters of prohibition argue the change would protect U.S. interests and avoid divided loyalties; sponsors repeatedly invoke “exclusive allegiance” language ^{[1] [2]}. Opponents, and legal scholars cited indirectly in coverage, note deep constitutional and judicial precedents protecting dual citizenship and flag likely legal challenges if Congress attempted a blanket ban ^{[1] [7]}. Coverage also points out practical hurdles: determining who holds foreign citizenship and enforcing renunciations would require new federal databases and procedures ^{[1] [2]}.

6. What to watch next — where empirical answers could come from

If Congress moves forward, expect two things in the record: bill hearings that might produce compiled lists or estimates of public officials with foreign citizenship, and executive-branch rulemaking that would create registries revealing country-by-country counts. Until such official disclosures or investigative datasets appear, journalists and scholars will be limited to anecdote and partial reporting ^{[1] [2]}.

7. Bottom line for your original query

Current reporting documents specific high-profile foreign ties but does not identify which foreign countries are most common among U.S. lawmakers; the available sources do not present a ranked country list or robust statistics on lawmakers’ second nationalities ^{[4] [8]}. For a definitive answer you will need either an authoritative dataset compiled by Congress or an investigative survey of elected officials’ citizenships—neither of which appears in the supplied sources ^{[1] [8]}.