Previously, immigrants who became U.S. citizens faced denaturalization only if they concealed their Nazi backgrounds, were linked to terrorist activities, or falsified their citizenship applications—usually affecting fewer than a dozen individuals annually.

However, during President Donald Trump’s first term, he initiated a campaign aimed at denaturalizing thousands of immigrant U.S. citizens, although he did not achieve those targets. Last week, Trump reactivated this initiative by directing that “adequate resources” be allocated for denaturalizing certain U.S. citizens as part of his broader immigration restrictions agenda.

Among his Day One executive orders was a brief mention of enforcing a component of immigration law allowing the government to revoke citizenship if it was “unlawfully procured.”

This directive falls under an order titled “Protecting the United States from Foreign Terrorists and Other National Security and Public Safety Threats,” signaling that denaturalization will be included in his tougher stance on immigration, according to Amanda Frost, a law professor and immigration attorney at the University of Virginia.

“We witnessed the outcomes during the previous term,” Frost commented. “Significant resources were committed to denaturalization.”

Trump’s latest directive gained little attention due to a series of more eye-catching orders intended to carry out his promised mass deportations. Within the first week, he declared a national border emergency, sent 1,500 troops to the border, including combat units, and authorized numerous federal law enforcement officials to arrest immigrants, among other actions.

Last week’s unnoticed directive is alarming for immigrant advocates, particularly because of the broad scope his administration cast during its earlier campaign.

“Ever since the executive orders were issued, there is a pervasive sense of fear,” stated Gintare Grigaite, a New Jersey immigration attorney who successfully challenged a denaturalization case during Trump’s first term. She has been receiving calls from anxious clients, including those who are already citizens.

“People are raising various hypothetical questions,” she noted. “Is there a legal avenue for someone to attempt to revoke their naturalization? If everything was disclosed truthfully, they shouldn’t be worried. If they acquired citizenship legitimately, there shouldn’t be concern over denaturalization.”

‘Zero tolerance’ campaign

During Trump’s first term, then-Attorney General Jeff Sessions launched an investigation involving 700,000 naturalized citizens, targeting approximately 1,600 cases for court action. This denaturalization initiative was part of the administration’s “zero tolerance” policy, which gained notoriety for the prosecution of border crossers and the separation of families.

A representative from U.S. Citizenship and Immigration Services (USCIS), the body that reviews citizenship applications, referred inquiries to the White House, which did not respond to an email seeking comment.

Trump’s initial effort to probe naturalized citizens built on an initiative that began during President Barack Obama’s administration.

At that time, the transition from paper to digital fingerprinting by the federal government led Homeland Security officials to uncover numerous instances where naturalized citizens had previously been deported or had concealed criminal histories that USCIS could not detect. The Obama administration initiated a review aimed at denaturalizing any citizen with connections to foreign terrorist groups.

Obama’s review focused on individuals with possible affiliations with terrorist organizations, criminal backgrounds, or who represented national security threats.

“They overlooked the common discrepancies in an individual’s immigration history,” said Cassandra Burke Robertson, a law professor at Case Western Reserve University who has studied denaturalization efforts. “The Trump administration altered this approach. They allocated more resources toward the program and directed that denaturalization be pursued against anyone who might have potential grounds for it.”

This widened the criteria to include “discrepancies in documentation—even simple typographical errors or innocent mistakes in the immigration process,” she explained.

Research indicates that the first Trump administration did not achieve its objective of referring 1,600 cases for civil or criminal prosecution, which are the avenues for revoking citizenship.

Irina Manta, a law professor at Hofstra University, established a database of denaturalization cases. She tallied 168 such cases during the Trump administration and 64 during the Biden administration, suggesting that while the effort may have slowed, it did not cease in the past four years.

“You would expect that naturalization would be permanent, regardless of what actions individuals may take,” Manta remarked. “The government should not have the authority to revisit the issue five years later.”

Trump’s strategy—urged by the conservative Heritage Foundation’s Project 2025—has been much broader in scope. Mark Krikorian, executive director of the right-leaning Center for Immigration Studies, stated that a wider approach to identifying fraud or misrepresentations is reasonable.

“It’s about ensuring that rules are enforced as intended,” Krikorian stated. “It has to be broad because the immigration system has been too lenient.”

‘Targeted, very political’ Cold War effort

During the politically charged environment of the 1950s, the U.S. government wielded its power to revoke citizenship from immigrants deemed political adversaries—such as labor leaders, journalists, or government critics labeled as Communists, noted Frost, the law professor from the University of Virginia.

“It was a highly focused, politically driven campaign during the Cold War,” she observed.

From the two world wars into the 1950s, approximately 22,000 immigrants experienced citizenship revocation.

The Supreme Court prohibited politically motivated denaturalization actions in 1967, ruling that the government could only withdraw citizenship under circumstances of fraud or “willful misrepresentation.”

In the 25 years leading up to Trump’s first term, from 1990 to 2017, the average number of naturalized citizens targeted by the U.S. government was around 11 annually, according to Frost’s research.

Most of those individuals had committed war crimes or other serious offenses and lied about their past to gain citizenship.

“During Trump’s first administration, we observed a significant rise in denaturalization actions,” Burke Robertson noted. “It’s evident that the current administration appears to be resuming from where the last one left off.”