Sen. Bernie Moreno’s Exclusive Citizenship Act of 2025 could force millions of dual nationals—especially Mexican Americans—to choose between passports.
On December 1, 2025, Senator Bernie Moreno (R-OH) introduced the Exclusive Citizenship Act of 2025. The bill would prohibit any person from simultaneously holding U.S. citizenship and citizenship of another country.
If approved, it would affect millions of citizens of other countries who have called the U.S. home. Mexico would be one of the most affected; it is estimated that around twelve million Mexicans reside in the U.S., and some of them have already obtained U.S. citizenship.
Exact figures are not available.
The appeal of dual citizenship appears to be in line with shifting migration trends in the last 15 years, said Ariel G. Ruiz Soto, a senior policy analyst at the Migration Policy Institute, who presented at an online seminar on dual nationals hosted by the Mexican government last year.
An improving Mexican economy has helped spur the voluntary return of a significant number of expatriates, so that the population of Mexican immigrants in the United States has shrunk to about 10.7 million from its 12.2 million peak in 2007, according to the Pew Research Center.
The major provisions include:
An effective date 180 days after enactment.
The requirement that existing dual citizens would have one year to renounce all foreign citizenships or relinquish U.S. citizenship.
The failure to renounce foreign citizenship within the one-year period would be treated as a voluntary relinquishment of U.S. citizenship under Section 349(a) of the Immigration and 26 Nationality Act (8 U.S.C. 1481(a).
The voluntary acquisition of a foreign citizenship after enactment would trigger immediate loss of U.S. citizenship.
The legislation would require the Departments of State and Homeland Security to establish verification procedures and update federal records accordingly.
Senator Moreno’s office states that the bill is intended to ensure “sole and exclusive allegiance” to the United States. The senator, who was born in Colombia and renounced Colombian citizenship at age 18 upon naturalization, has described U.S. citizenship as “an honor and a privilege” that should not be shared with another nation.
Impact of the Exclusive Citizenship Act of 2025
The bill would affect:
Naturalized citizens who retain their original citizenship.
U.S.-born children of foreign-citizen parents who acquire a second nationality at birth.
Foreign children born of a U.S. citizen and foreign parent who acquires both citizenships at birth.
Individuals who marry a foreign national and under the laws of that country automatically acquire the foreign spouse’s citizenship.
Individuals who later naturalize abroad.
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