It appears that President-elect Donald Trump intends to keep his campaign promise to begin deporting at least 15 million people who, he claims, have been “poisoning the blood” of our country. By at least one estimate, it will be virtually impossible — logistically and financially — to implement Trump’s grandiose ambitions, but that won’t keep him from destroying countless lives while trying.

One initiative, smaller in scale but potentially devastating in its impact, will be aimed at immigrants who have become naturalized U.S. citizens.

Trump has named three deportation hardliners to key positions in his administration, including Stephen Miller as deputy chief of staff for policy, Kristi Noem for secretary of Homeland Security and Tom Homan as “border czar.”

Miller is likely to be especially influential and especially brutal.

“America is for Americans only,” he shouted at Trump’s Madison Square Garden campaign rally. In a pre-election interview, he outlined a sweeping plan to use the National Guard, state and local police, the Drug Enforcement Agency, the Bureau of Alcohol, Tobacco and Firearms and even the U.S. military to round up undocumented immigrants and detain them in tent camps until they can be expelled.

But even “documented” immigrants will not be safe, because Miller has declared that he will pursue the seldom-used process of “denaturalization” to go after people who have been citizens for years or decades, based on suspicions about purported fraud on their naturalization applications. Individuals stripped of citizenship will then be subject to deportation along with Miller’s other targets.

Not every discrepancy or inconsistency is evidence of fraud, of course, so it is inevitable that some legitimate citizens, or those who made minor mistakes based on confusion, may be caught up in an overzealous investigation.

The process for invalidating naturalization was created by statute in 1906, providing that citizenship may be canceled if it was obtained through false statements or fraudulent omissions. It was used inconsistently in the 20th century, with periods of intense activity during the World Wars and the Cold War, and much less often in less parlous times.

By the early 21st century, denaturalization was mainly sought for accused terrorists, war criminals and human rights violators who had concealed their backgrounds on their visa and citizenship applications. During the Obama administration, for example, a successful denaturalization case was initiated against Rasmea Odeh, who had concealed her previous conviction for a supermarket bombing in Israel that had killed two university students.

During the first Trump administration, the Department of Justice established a new denaturalization effort called “Operation Second Look,” tasked with investigating the citizenship of thousands of immigrants suspected of obtaining naturalization by fraud, misrepresentation, or deceit.

Operation Second Look hired scores of new agents, initially more than tripling the number of active denaturalization cases and promising many more. While Democratic administrations had “focused on those who have done something terrible,” the Trump investigators appeared primed to go after “people who did nothing of note, or whose wrong caused no harm.”

In 2017, the Supreme Court limited the government’s ability to revoke citizenship, unanimously holding that naturalization can only be canceled for “materially” false statements, meaning a lie or intentional omission that would have precluded naturalization in the first place.

Materiality, however, is in the eye of the beholder — or in this case of Stephen Miller, who has declared that he will revive a “turbocharged” Operation Second Look in 2025, consistent with his intention to strip as many immigrants as possible of citizenship as a prelude to deportation.

Miller’s obsessive denaturalization campaign can have extreme consequences, and not only for those immigrants who, rightly or wrongly, find their citizenship challenged or canceled. Even those who successfully defeat a denaturalization case will have been subjected to tremendous stress.

As journalist M. Gessen explained, an expansive hunt for invalid naturalization applications can turn millions of naturalized citizens into second-class citizens, by “taking away their assumption of permanence.”

Even worse, thousands of immigrants, naturalized as minors through a parent’s application, may have their citizenship annulled through no fault of their own. Perhaps worse still, if that is imaginable, many American-born children might find their citizenship in doubt if their parents are denaturalized, given Trump’s pledge to end birthright citizenship for the children of undocumented immigrants.

Fortunately, denaturalization is a judicial process, with a right to trial in federal court. Unfortunately, there is no right to appointed counsel in denaturalization cases, so every accused defendant will also bear the expense of retaining a lawyer.

For the many without funds for an attorney, there is a significant chance of losing citizenship by mistake or default, which may be exactly what Stephen Miller has in mind.