The Myth: This is an intriguing and complicated one, because prominent economists disagree about some of the data. When it comes to the wider U.S. population, though, the idea of immigrants threatening U.S. job security and depressing wages is pretty common: the International Business Times cited studies in 2015 showing that 51 percent of Americans, and around 70 percent of GOP voters, appeared to believe that their jobs were under threat from immigrants, particularly undocumented ones. The reality, however, is not that immigrants to the U.S. are gobbling up jobs left and right. It's more nuanced than that.
The Truth: For one, the jobs pursued by immigrants are often quite different to those pursued by native-born Americans of the same skill level. They're not competing for or stealing jobs in the same area, according to census data of 16 million Americans published in 2015. The people seen as most vulnerable to immigrant competition are native-born Americans without high school diplomas, but it seems, according to the study, that they and immigrants actually take quite different low-skilled jobs, with immigrants taking maid and housekeeping jobs, agricultural work, cooking and construction work, while low-skilled native-born Americans tend to go towards cashier jobs, sales work, behind-the-scenes stock jobs, and waiting jobs at restaurants. There's some overlap, but less than you might imagine.
And that matters, because a lot of the worry about immigrants centers on these low-skilled jobs and how migrants create more competition and lower wages. There is possibly some cost to native-born Americans in this bracket, but with less competition from migrants, it's not as pronounced as it could be. (There's a lot of dispute among economists about what migrants have really done to the wages of lower-skilled Americans; some argue definitively that there's a recognizable gap, while others argue against it. The most notable study about this comes from Miami, where a sudden influx of low-skilled Cuban immigrants in the 1980s was studied for its effects on everybody's wages and employment. Startlingly, there was no impact at all; migrants didn't depress wages or cast anybody out on their ear.)
The days of mostly lower-skilled new migrants are also likely to be over. According to a 2017 study of the census, immigrants arriving in the U.S. in recent years are far more educated on average than those in previous immigration waves; 48 percent of the ones who arrived between 2010 and 2015 have at least a bachelor's degree. Competition among highly-skilled workers is different to lower-skilled ones, because it's much harder to substitute one worker for another. The ACLU notes that "immigrants are blamed for unemployment because Americans can see the jobs immigrants fill but not the jobs they create through productivity, capital formation and demand for goods and services." Immigration in general boosts wealth levels, spurs market innovation and is particularly good for creating jobs — especially in businesses started or joined by higher-skilled immigrants.