Blaming immigrants is obviously more politically useful than, say, blaming robots. But the truth is that automation has affected low-skilled jobs far more than immigration, and that trend will continue whether or not we build a border wall. In just the last two years, 320,000 industrial robots have been sold, vastly increasing efficiency—not just in industrial applications but also in the service sector. As more uses are found for automation across the economy, productivity will continue to rise even as job growth slows.

New technology is even changing the sector most associated with migrant labor: farms. Crop-picking robots aren’t that far off, and farm owners in the U.S. are keen to invest in research and development, in part because of a growing shortage of farm workers. More than half of all farm workers are illegal immigrants, but that labor pool is shrinking, in part because more Mexican immigrants are leaving the country than are coming in, according to a 2015 report from Pew. That means more competition among farms to attract workers, which means higher wages. According to a CNN report last week, the competition for farm workers has boosted wages to $12 an hour, more than California’s $10-an-hour minimum. Some farms are paying as much as $15 an hour.

And while California farms are competing for immigrant labor at those wages, they can’t seem to attract American workers. Tom Nassif, CEO of a trade organization called Western Growers, tells CNN, “Americans want stable jobs with vacation and other benefits. That doesn’t exist in agriculture.”