Despite the pervasive rhetoric of President-elect Donald Trump, small businesses across the U.S. cite the need for more Mexican workers in their ranks. Employers who rely on low-skilled workers for survival — like those in the hospitality, construction, and agricultural industries — say that they’re struggling due to the shortage of immigrants looking for work.

These businesses are having a lot of trouble filling their employment vacancies. While roofing companies can be highly profitable — on the lower end, the typical homeowner spends 1-4% of their house’s value every year on maintenance and repairs — businesses like these are actually having to turn down work, simply because they don’t have the laborers to take on the job. Case in point, Dallas’s King of Texas Roofing Co., which had to turn down $20 million worth of projects over the last two years due to a lack of workers.

Nelson Braddy Jr., owner of King of Texas Roofing Co., says that “without Mexican labor, our industry is at a standstill. It’s the worst I have seen in my career.” Contrary to Donald Trump’s main campaign message, the issue is not that there are too many Mexicans coming into the country — it’s that there are too few.

Unlike what Trump’s supporters believe, these undocumented immigrants are not competing with American workers for these low-skill jobs. The demanding nature of these positions, combined with the trend of Americans pursuing college degrees, mean that fewer U.S. citizens have their sights set on jobs within the construction, hospitality, or agriculture fields.

What’s more, the flow of undocumented immigrants is the lowest it’s been in decades. Nowadays, the influx has slowed to around 100,000 a year — a figure that’s remained fairly steady since 2009. In the mid-2000s, those numbers hovered around 350,000 a year, but in the late ’90s and at the dawn of the millennium, the totals were upwards of half a million. In fact, there were only 337,117 apprehensions of illegal immigrants by the U.S. Border Patrol. That’s the lowest that number has been in 45 years.

Pia Orrenius, a senior economist at the Federal Reserve Bank of Dallas, says that “mass migration from Mexico is over. Low-skilled labor will never be as plentiful again.”

The shortage of workers in these areas is well documented. In May of this year, the combined vacancies for the restaurant and accommodations sectors totaled 700,000. Last year, the Associated General Contractors of America found that 86% of construction companies were struggling to fill job openings for electricians, carpenters, and more. There’s already a caregiver crisis in some states, and the Labor Department expects the problem to only get worse: they’re predicting the demand for home aides will increase by 40% over the next ten years.

What Trump and his supporters fail to realize is that by deporting immigrants, they’re not opening up the job market for willing Americans. Those jobs are already open, and U.S. workers don’t want them. While some are hopeful that the new administration will help to solve the labor shortage, it seems inevitable that these plans will only make a bad situation worse.