Construction workers in California are making less than they made 40 years ago.

Natalie Kitroeff of The Los Angeles Times reports that construction workers in California are making less in 2017 than they did 40 years ago, after adjusting for inflation. The reason? The shift from a heavily unionized labor force to a largely non-union labor force that is 70 percent Latino and heavily immigrant.

The LA Times story follows a Breitbart News report in March that revealed that nation-wide the inflation-adjusted wages of construction workers in 2017 are lower than they were 56 years ago.

According to Kitroeff, construction jobs grew less lucrative as immigrants flooded into California, many of whom looked for employment in construction jobs.

In the span of a few decades, Los Angeles area construction went from an industry that was two-thirds white, and largely unionized, to one that is overwhelmingly Latino, mostly nonunion and heavily reliant on immigrants, according to a Los Angeles Times review of federal data.

At the same time, the job got less lucrative. American construction workers today make $5 an hour less than they did in the early 1970s, after adjusting for inflation.

In 1972, construction paid today’s equivalent of $32 an hour, almost $10 more than the average private-sector job. But real wages steadily declined for decades, erasing much of that gap.

Kitroeff  points out that this shift in the construction industry reflects the narrative that President Trump pushed as a candidate throughout 2016, arguing that he would protect the nation’s borders so that American jobs and wages would be protected.

Despite this, some claim that immigrants are not the cause of the decline in construction wages.

“Immigrants are not the cause of this, they are the effect,” said Ruth Milkman, a sociologist who has done research on the history of construction in Southern California. “The sequence of events is that the de-unionization and the accompanying deterioration of the jobs come first, before immigrants.”

Milkman concedes that the influx of immigrants (immigrants working construction in California construction has jumped from 13% in 1980 to about 43% today) made it easier for project managers to shun union labor.  In other words, without the additional laborers created through a loose border policy and tens of millions of immigrants, employers would not have been able to de-unionize and push down wages.

Still, some argue that most Americans don’t want the jobs that are being taken by immigrants. Tom Brown, head of an engineering contracting firm in San Diego, has hit back against this argument, claiming that those who suggest that Americans don’t want those jobs are being dishonest.

“Look at the heart of America, the coal workers and the miners,” he said. “People aren’t being honest when they say Americans don’t want it.”

Tom Ciccotta is a libertarian who writes about economics and higher education for Breitbart News. You can follow him on Twitter @tciccotta or email him at tciccotta@breitbart.com