Kamala Harris had no sooner replaced Joe Biden as the presumptive Democratic presidential nominee than Donald Trump began bashing her over the number of immigrants coming into the U.S., declaring they had driven countless American workers from their jobs.

But the data on U.S. employment and the economy overwhelmingly suggest a reality far more beneficial when it comes to immigration than the nightmarish vision the former president has put forth.

The surge of international migrants since 2021 — including refugees, asylum seekers and others entering legally and illegally — has lifted the U.S. and California economies by filling vacant jobs, helping to keep job creation strong, growing businesses and pumping millions of tax dollars into state, local and federal coffers.

Payroll taxes on immigrant workers have even helped relieve pressure on the nation’s embattled Social Security system.

There are, of course, short-term public costs associated with acclimating so many new arrivals, plus government expenditures on education and health services for immigrants and their families, along with the political and social challenges. Many agree the current immigration system is flawed and chaotic.

But from a budgetary perspective, the additional federal spending on immigrants is projected to pale next to the increase in revenues from the millions more people working, paying taxes and buying goods and services, according to the Congressional Budget Office.

And more than a few economists say that, by easing the shortage of American workers as the U.S. population grows older and birth rates decline — particularly in California — immigrants have played a large and positive role in maintaining a healthy, growing economy.

“This is the hottest labor market that has existed in two generations,” said Michael Clemens, an economist at George Mason University who specializes in international migration. “That means there have never been as many opportunities for immigrants and natives to mutually benefit each other through economic interaction in the last half century.”

Without immigration, California’s workforce would have fallen well short of its needs, especially since the high cost of living, soaring home prices and other factors have fueled a notable outflow of population from the state.

From 2021 to 2023, the population of U.S. citizens 16 years and older living in California fell by 625,000, according to data from the U.S. Bureau of Labor Statistics, while employment increased by 725,000.

Over that period, however, the unemployment rates for native-born and foreign-born Californians fell by similar levels — an indication that immigrants are not taking away American jobs.

Moreover, the recent waves of migrants are filling lower-paying, more physically demanding positions that do not attract as many native-born Americans, at least not at the wages that are offered.

“Immigrants are a really important source of the labor force for California, in the high end as well as in a lot of jobs that don’t pay as well,” said Hans Johnson, a demographer at the Public Policy Institute of California.

Separate employers’ data from the Bureau of Labor Statistics show that more than 70% of the nearly 400,000 payroll jobs added in California between June 2022 and June 2024 have been in two industries: social assistance, such as health services for the elderly and child care; and leisure and hospitality. Both sectors are heavily dependent on immigrant workers.

Employers in construction, another industry reliant on immigrant labor, also added thousands of jobs in that period.

“A lot of what we do is physical — you get on your knees. And Americans don’t do that,” said Tom Straus, owner of Straus Carpets. He’s been in the flooring business in the Bay Area for almost half a century and has regularly hired Latino immigrants. “The work is excellent and strenuous,” he said.

Some 3.3 million immigrants arrived in the U.S. last year, after net immigration of 2.6 million in 2022, according to estimates by the Congressional Budget Office. Those numbers are roughly triple the annual average in the prior decade. A similarly large number is expected this year, although immigration over the long haul is likely to return to around 1 million a year, experts say.

No one knows how many immigrants who arrive in California decide to stay here. Over the years, increasing opportunities in other states and California’s high cost of living have made it less attractive as a final destination. The latest Census Bureau figures, for 2022, show 27% of California residents are foreign-born.

Most of the immigration increase in recent years has been driven by foreign nationals entering illegally, asylum seekers and hundreds of thousands of people from Ukraine, Venezuela, Haiti and other countries who entered under humanitarian programs and can apply for work authorization.

Since 2021, U.S. border patrol officers have seen a surge of migrants from Mexico, Colombia, Ecuador and Peru — but also from countries such as China and India, whose citizens in the past had rarely sought to come through the southwest border, Department of Homeland Security statistics show.

Over the last few years, about 6 in 10 people crossing unlawfully have been turned away, according to an analysis of DHS data by Clemens, the George Mason professor. Most of those who are detained and not expelled are released in the U.S., many because they have shown evidence of fear and a desire to apply for asylum.

“There’s no doubt the economy is better off because of immigration,” said Christopher Thornberg, founding partner at Beacon Economics, a research and consulting firm in Los Angeles.

“At one level, I understand people are nervous about folks coming here in an uncontrolled way,” he said, noting that he fears the anti-immigrant drumbeat is getting louder and louder.

“But our nation desperately needs people,” he said. “People have stopped having babies, and so many are going into retirement. And here we really have an opportunity to help our economy in the long run, and we are turning away from it.”