The Trump administration has said the immigration overhaul it announced this week will ensure that new legal residents carry their own weight, without prejudice or favor. Yet the new rule for weeding out those who might be a drain on taxpayers will almost certainly disadvantage poor people from Latin America, Africa and parts of Asia.

Over time, people who are granted green cards — the major step toward winning citizenship — will become wealthier but their numbers will shrink, researchers predicted. More green cards will go to immigrants with a good education and a measure of self-sufficiency; fewer will be granted simply because someone has a family member in the United States.

Immigrants from Europe and Canada are least likely to face problems under the new regulations, according to one study, which found that, by contrast, nearly three-quarters of recent arrivals from Mexico and the Caribbean have relatively modest incomes that would jeopardize their chances at a green card.

“Never before in our history have we closed off the American dream to strivers who aren’t already middle class,” said Doug Rand, who worked on immigration policy in the Obama White House and co-founded a technology company that helps immigrants obtain green cards. “This is an attempt to turn back the clock and dramatically change the face of new Americans.”