The ranks of immigrants and their children will grow to reach a record share of the US population in the second half of this century, projections show, with Asian immigration taking over as the biggest source of population growth.

The forecasts demonstrate the extent to which immigration will reshape the US population, even as politicians such as Republican presidential frontrunner Donald Trump use hostility towards foreigners to appeal to parts of the electorate.

The report from the Pew Research Center finds that foreign-born individuals and their children will comprise 36 per cent of the US population by 2065, higher than the peaks reached at the beginning of the 20th century and up from 26 per cent now. The ranks of foreign-born individuals alone will also rise to a record.

The research finds that the driver of US population growth over the next five decades will be immigration from Asian countries such as China, India, Korea and the Philippines, with the expansion overtaking arrivals of Hispanics.

By 2065, Asians are projected to become the largest immigrant group, at 38 per cent of the immigrant population, surpassing Hispanics, at 31 per cent. Overall, the immigrant population will reach 78m by 2065, compared with 45m today, with a growth rate double that of the US-born population.

The outlook comes as controversy over immigration plays out in the presidential election debate. Mr Trump’s attacks on Mexicans and calls for a wall to be built on the southern US border have raised fears among Republican strategists that the party will alienate Hispanic voters at a time when they are becoming a powerful voice at the ballot box.

His words play on a belief that illegal immigrants are still flooding into the US, and they come as the US continues to struggle with its bitter debate over pathways to citizenship for unauthorised immigrants.

Yet the ranks of unauthorised immigrants in the US actually stayed static between 2009 and 2014, Pew numbers showed, as illegal arrivals from Mexico slowed sharply. “We are basing our trends on the patterns we have seen over the last 10 years or so,” said Jeffrey Passel, senior demographer at the research centre. “We are projecting larger flows from Asia than Latin America.”

Pew polling shows people are divided over the benefits of immigration. Among Democrats, 55 per cent say immigrants are making US society better in the long run, while 24 per cent say immigrants are making things worse, with the rest arguing they are not having much effect.

By contrast, among Republicans views are nearly the opposite: 53 per cent say immigrants are making society worse in the long run, while 31 per cent say they are making things better.

A growing US population, fuelled by arrivals of well-qualified foreigners, should be supportive of economic growth, at a time when many advanced countries face more ageing populations. The profile of those arriving shows they are well educated — and more likely than US-born adults to have a university degree.

Bill Frey, a demographer at the Brookings Institution, said: “This pushback about undocumented immigration which tends to dominate political debates put to the backburner a more rational discussion about immigration policy. We are going to have to have a reasonable flow of immigration to the US to keep our labour force robust.”

The US population is expected to reach 441m by 2065, compared with 324m today, with 88 per cent of the increase linked to future immigrants and their descendants, according to the report.

The Pew projections extrapolate from recent migration trends, and so are susceptible to unexpected changes in US economic fortunes and legislation, as well as those of other big countries.