Senator Bernie Moreno has introduced a sweeping proposal that would end dual citizenship in the United States, forcing millions of Americans with ties abroad to choose a single nationality or face automatic loss of their U.S. citizenship. The bill marks one of the most far reaching attempts in recent years to narrow the definition of what it means to be an American, and it is already drawing sharp warnings from legal experts, civil rights groups, and immigrant communities.

Moreno, who immigrated from Colombia before becoming a U.S. citizen, framed his proposal as a matter of “exclusive allegiance.” His bill would require anyone holding citizenship in another country to renounce it if they wish to keep their U.S. status. Those who do not comply would be stripped of their citizenship automatically, regardless of how long they have lived in the country, whether they were born here, or how deeply rooted they are in American life.

Critics argue the measure would upend decades of accepted legal norms. Dual citizenship is currently recognized under U.S. law and held by an estimated several million Americans, including children of immigrants, individuals born abroad to American parents, and people who maintain legal ties to their family’s country of origin. Ending it would raise immediate constitutional questions about due process, equal protection, and the government’s ability to revoke citizenship without individualized review.

Immigrant rights groups warn the bill could destabilize families, strip rights from naturalized citizens, and create a climate of fear for communities already facing political pressure. Policy analysts note that the proposal mirrors hardline efforts in other countries to limit the political participation of dual nationals and could force Americans to give up inheritance rights, family connections, or legal residency abroad.

Legal scholars also point out that citizenship revocation has historically been one of the most extreme powers a government can exercise. Any automatic or mass revocation system, they say, risks violating Supreme Court precedent and international human rights standards.

As the proposal moves forward, opponents describe it as a solution in search of a problem. They argue it frames millions of law abiding Americans as inherently suspect for maintaining cultural or familial ties outside the United States. For many, the bill reads less like a tightening of policy and more like an attempt to redefine national identity in a way that excludes the country’s own diverse population.