The harvest had just begun when agents from the Immigration and Naturalization Service stormed across the onion fields of Vidalia, Ga., in 1998, sweeping up 21 immigrants who were trudging behind tractors without legal authorization to work in the United States, pulling onions out of the ground for 75 cents per 50-pound bag.

The fallout was unexpected. Senator Paul Coverdell, Republican of Georgia, wrote to the immigration service, complaining of its “indiscriminate and inappropriate enforcement tactics,” against “honest farmers who are simply trying to get their products from the field to the marketplace.” Representative Saxby Chambliss blasted the immigration officials’ “bullying tactics.”

And immigration enforcement caved: Shortly after the raid, onion growers in 19 counties were granted a temporary amnesty to keep their workers as long as their paperwork looked legitimate.

Welcome to reality.

Last week, Donald J. Trump was elected president based on a straightforward promise to make the United States great again. He aimed his message primarily at tens of millions of white working-class Americans who feel left behind in the growing economic prosperity, undercut by the advancement of minorities and women, competition from illegal immigrants at home and cheap workers in other countries.