Republicans have a net-zero goal they can finally get behind: not for carbon emissions but for immigration. And they may achieve it as soon as this year. In a July white paper, three economists projected that, in a remarkable departure from decades-long patterns, more foreign-born people will likely leave the United States in 2025 than will enter. In the three months since, the Trump administration’s aggressive actions have driven net migration even lower than expected, one of the authors, Wendy Edelberg of the Brookings Institution, told me. Student-visa numbers are lower than previously anticipated. In September, the Department of Homeland Security boasted that since President Donald Trump’s return to office, it had deported 400,000 people, more than triple the pace of deportations under the Biden administration; it has billions more to spend on further enforcement efforts, courtesy of Congress and the One Big Beautiful Bill Act. An unknown number of people have voluntarily left the country rather than be forced out.

We will not know with certainty for some time whether America has hit net zero, but the White House is already claiming victory. “Promises Made. Promises Kept. NEGATIVE NET MIGRATION for the First Time in 50 Years!” Trump declared on Truth Social in August. Prompted by a CNN report, that claim could, if anything, prove to be too restrained. If the United States experiences negative migration in 2025 and, as seems likely, 2026, it will probably be the first net outflow in nearly a century.

To “America First” true believers, the recent trend heralds a return to a halcyon era. “Finically [sic], culturally, militarily—immigration was net negative. All population growth was from family formation,” Stephen Miller, Trump’s deputy chief of staff, wrote on X in August. The best data we have, derived from the decennial census, suggest that Miller was incorrect. In the buoyant decades after World War II, net migration was low compared with the Ellis Island era of the early 20th century, but still positive. According to census data, the only decade in American history when migration was net negative was the 1930s—during the Great Depression.

From the September 2024 issue: Seventy miles in hell

For the past decade, nativism has proved politically potent enough to carry Trump to the Oval Office twice. It may be powerful enough to bring net migration down to zero, perhaps for some time. If that happens, the America that emerges will be reduced, not just by lower economic growth but also by a shrinking population.