Which past U.S. senators have held dual citizenship and how was it disclosed?

Checked on December 12, 2025
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Executive summary

Several well-known U.S. senators have held or been reported to hold dual citizenship; prominent examples in recent reporting include Ted Cruz (U.S. and Canada) and Tammy Duckworth (U.S. and Thailand), and many senators have been born abroad though not all retain foreign nationality [1] [2]. News coverage shows no single public registry of dual citizens in Congress and no consistent disclosure mechanism; proposals this year would force disclosure or ban dual citizenship for members [3] [4].

1. A short list of senators publicly linked to dual nationality

Reporting and compilations list past and present senators who were born abroad or have held foreign nationality; for example, Ted Cruz’s Canadian birth and past Canadian citizenship and Tammy Duckworth’s Thai connection are cited in media summaries that note some senators “have dual citizenship” [1]. The Senate directory documents many foreign-born senators but does not itself assert who holds foreign passports today [2].

2. Birthplace ≠ current dual citizenship — the reporting gap

Federal records and press accounts make a clear distinction between being foreign‑born and actively holding dual citizenship. The Senate’s directory tallies foreign‑born senators and constitutional qualifications but does not maintain a list of dual citizens, which leaves journalists and the public relying on biographical reporting and personal statements [2]. As a result, available sources do not offer a comprehensive roster of every senator who currently holds a second citizenship.

3. How dual citizenship has been disclosed historically

Disclosure typically occurs through personal biographies, campaign filings, media investigations, or a public renunciation announcement. Examples in the recent coverage include politicians who have publicly stated they renounced a foreign nationality — Senator Bernie Moreno is repeatedly reported to have renounced Colombian citizenship when he naturalized at 18, and that personal history is part of his public pitch for anti‑dual‑citizenship legislation [5] [6]. There is no indication in the supplied sources of a formal, standardized disclosure form used historically for Congress members [2].

4. New political pressure: bills to require disclosure or to ban dual citizenship

Multiple 2025 proposals aim to change current practice. Representative Thomas Massie introduced the “Dual Loyalty Disclosure Act” to require political candidates to disclose dual citizenship, and Senator Bernie Moreno introduced the “Exclusive Citizenship Act of 2025” to prohibit holding U.S. citizenship simultaneously with another nationality; Moreno’s bill would require people to renounce foreign citizenship or face loss of U.S. citizenship and would compel government recordkeeping and coordination across agencies [4] [3] [6]. News outlets report critics view such measures as politically motivated efforts to restrict citizenship rights [7].

5. Legal and practical obstacles flagged by reporting

Journalists and analysts note substantial legal and administrative hurdles. Coverage of Moreno’s bill emphasizes that current constitutional and administrative rules make automatic expatriation controversial and that the U.S. does not keep a comprehensive registry of dual citizens, complicating enforcement [8] [3]. News analysis also points out that ending dual citizenship for officeholders or citizens could implicate constitutional issues and face challenges in courts [9].

6. Two competing narratives in public debate

Proponents frame dual‑citizenship limits as protecting undivided allegiance; Senator Moreno frames his bill through his personal experience as a naturalized citizen who renounced another nationality and calls for “sole and exclusive allegiance” [6] [5]. Opponents and some legal scholars argue disclosure and bans are unnecessary overreach that would penalize naturalized citizens and immigrant communities and could be used as a partisan tool to stigmatize political opponents [7] [3].

7. What readers should take away

Current reporting establishes that some senators have had foreign citizenships or foreign births and that disclosures have been ad hoc — through biographies, news stories, or personal renunciations — rather than centralized filings [1] [2]. Proposed legislation would formalize disclosure or ban dual citizenship, but sources show serious logistical and constitutional questions that would shape any enforcement or litigation [3] [8]. Available sources do not provide a definitive, exhaustive list of every past U.S. senator who ever held dual citizenship; such a list is not found in the reporting provided [2].

Want to dive deeper?
Which current or former U.S. senators have held dual citizenship with specific countries?
How do Senate disclosure rules address dual citizenship and foreign allegiances?
Have any senators been required to renounce foreign citizenship to serve, and what were the legal outcomes?
How has dual citizenship of members of Congress affected confirmation hearings, elections, or legal challenges?
Where can I find official records or news reports documenting senators' citizenship status and disclosures?