New Delhi, May 27 -- "GREEN CARD", released in 1990, is one of the few romantic comedies built around immigration law. In the film Gerard Depardieu plays a French waiter living and working illegally in New York City. Andie MacDowell plays an environmentalist who marries him so that he can obtain a "green card", as America's permanent-residency permit is known. Alas, if President Donald Trump gets his way, the film's premise may no longer work. In a move seemingly designed to slow legal migration-not just ruin mediocre films-the administration wants applicants to leave America before applying for a green card.

The change would be dramatic. Since 1952, when Congress passed the Immigration and Nationality Act, America has allowed eligible f...