America's population could decrease as much as 32% if the US were to completely close its borders

Donald Trump's proposed immigration crackdown, including mass deportations, has been criticized as potentially inflationary, but experts warn it could also worsen the issue of an aging population in the U.S.

Immigration and Demographics

Immigration has long been viewed as a solution to America’s declining birth rate, which contributes to an aging population and a shrinking workforce. Curtailing immigration could accelerate these demographic shifts, says Alan Berube, a senior fellow at the Brookings Institution.

Trump's campaign promises include deporting the estimated 11 million unauthorized migrants in the U.S., banning refugees from certain countries, and reinstating travel bans. These policies could significantly reduce immigration flows.

A Brookings projection suggests that if net migration drops to "low" levels—defined as 350,000 to 600,000 migrants per year—the U.S. population could shrink by 4% by 2100. A complete border closure would lead to a dramatic 32% population decline by the end of the century.

Economic Impact of Fewer Immigrants

Berube noted that Trump's policies would likely fall somewhere between these extremes but warned of the consequences. A shrinking workforce would increase the burden on the remaining population to support a growing number of retirees. In a "low immigration" scenario, the 65-and-older population would rise from 28% of the working-age population in 2022 to 57% by 2100.

"The U.S. workforce is aging faster than ever," Berube explained. "Cutting off immigrant labor will intensify the challenges tied to an aging population and workforce."

Economic Growth and Workforce Challenges

The U.S. birth rate hit a historic low in 2023, with just under 55 births per 1,000 women aged 15 to 44, according to the CDC. Immigration helps offset this trend, as immigrants tend to be younger and participate in the workforce at higher rates.

In 2022, about 8.3 million unauthorized immigrants were working in the U.S., according to Pew Research Center data. Industries like construction and agriculture, which rely heavily on undocumented workers, are particularly vulnerable to labor shortages. Construction already faces an annual worker shortfall of 200,000 to 400,000, said José Torres, a senior economist at Interactive Brokers.

Policy and Public Perception

Trump and the Republican Party argue that stricter immigration policies will lower costs for healthcare, housing, and education. “The American people re-elected President Trump by a resounding margin, giving him a mandate to fulfill his campaign promises. He will deliver,” said Trump spokesperson Karoline Leavitt in a statement.

A Complicated Path Forward

While immigration alone cannot solve the demographic crisis, Berube emphasized its critical role as a "band-aid" solution. "Immigration offsets aging trends and fills gaps in the labor market. Without it, economic challenges tied to a shrinking, aging workforce will become far more severe."