DURANGO, Mexico — For decades, U.S. farmers, landscapers and builders tapped a seemingly endless supply of cheap labor: the waves of undocumented immigrants coming across the southern border. The workers arrived in time for harvests and construction booms. They did the low-wage manual labor that Americans were unwilling to do.
By the 2000s, more than half of American farmworkers were undocumented, according to the Labor Department. But now — thanks to border enforcement, the surging cost of smugglers and changes in migration patterns — the number of people crossing into the United States illegally is nearing the lowest level
in decades . There are more Mexicans leaving the United States than arriving there.
For the White House, that might be a triumph. But for the agriculture industry, the impact is acute. Each year, its labor force dwindles.