The share of the United States population that is foreign-born has reached its highest level since 1910, according to government data released last week. But in recent years, the numbers have been soaring not so much with Latin Americans sweeping across the border, but with educated people from Asia obtaining visas — families like the Patels, who have taken advantage of “family reunification” provisions that have been a cornerstone of federal immigration law for half a century.

Since the Patels began flocking to America in the 1970s, millions of other Indians have arrived to work as programmers and engineers in Silicon Valley, doctors in underserved rural areas and researchers at universities. The majority were sponsored by relatives who came before them. Others arrived on work visas and were later sponsored for legal residency, or green cards, by their employers.

The Trump administration has framed immigration as a threat to the nation’s security and to American workers, a drastic departure from the longtime consensus that immigration was a net positive for the country. The president’s public priorities have often focused on fortifying the southwest border, but his administration is also working to scale back decades of legal migration that have led to Asians, not Latin Americans, becoming the largest group of new foreign-born residents since 2010.

Already, the administration has quietly begun taking steps to cut back legal immigration, under the banner of “Buy American and Hire American,” which the president framed in an executive order last year. Some experts predict that the number of immigrants granted permanent legal residency in the 2018 fiscal year, which ends on Sept. 30, will show a rare decline.

Without passing new legislation, the administration has pursued a number of policies that are slowing legal immigration. It has reduced refugee admissions; narrowed who is eligible for asylum; made it more difficult to qualify for permanent residency or citizenship; and tightened scrutiny of applicants for high-skilled worker visas, known as H-1Bs.