Alabama’s new anti-immigrant law, the nation’s harshest, went into effect last month (a few provisions have been temporarily blocked in federal court), and it is already reaping a bitter harvest of dislocation and fear. Hispanic homes are emptying, businesses are closing, employers are wondering where their workers have gone. Parents who have not yet figured out where to go are lying low and keeping children home from school.

To the law’s architects and supporters, this is excellent news. “You’re encouraging people to comply with the law on their own,” said Kris Kobach, the Kansas secretary of state, who has a side career of drafting extremist immigration legislation for states and cities, notoriously in Arizona and now in Alabama.

Alabama’s law is the biggest test yet for “attrition through enforcement,” a strategy espoused by Mr. Kobach and others to drive away large numbers of illegal immigrants without the hassle and expense of a police-state roundup. All you have to do, they say, is make life hard enough and immigrants will leave on their own. In such a scheme, panic and fear are a plus; suffering is the point.

The pain isn’t felt just by the undocumented. Legal immigrants and native-born Alabamans who happen to be or look Hispanic are now far more vulnerable to officially sanctioned harassment. Many of those children being kept home from school by frightened parents are born and bred Americans.