Matthew Kolken, a partner at a New York immigration law firm, said there are only two substantive ways Trump’s in-laws could gain green cards: by their daughter sponsoring them or by an employer sponsoring them. The latter is unlikely, as it would require a showing that there were no Americans who could do the job for which they were sought.

Both the Knavses are reportedly retired. In Slovenia, Viktor Knavs, now 73, worked as a chauffeur and car salesman. Amalija Knavs, now 71, was a pattern maker at a textile factory.

David Leopold, an immigration lawyer and a past president of the American Immigration Lawyers Association, said the first lady’s sponsorship of her parents appears to be the only reasonable way they would have obtained green cards because the process currently gives preferential treatments to parents of a U.S. citizen.