WASHINGTON – After almost a decade of languishing growth, the nation's immigrant population increased by more than 1 million last year amid stronger job creation in the U.S. and slowing economic activity in other parts of the world.

New government data show there were 42.4 million foreign-born people in the U.S. last year, or 13.3 percent of the country's total population. That's up 1.04 million from 2013, about double the annual growth in recent years.

The sharp increase in immigrants, most of whom came from Asia, contrasts with a small net decrease in immigrants in 2008 during the depths of the Great Recession. The surge has been felt especially in states such as California and Florida.

The upturn comes as illegal immigration becomes a highly contentious issue in the 2016 presidential campaign.

Paradoxically, ferment over illegal immigration rose in the past few years even as immigration numbers remained relatively low. The issue draws strength, in part, from voter concerns over stagnant wages, which some link to immigrants competing for jobs, as well as from worries over rapid changes in U.S. culture and society.

Republican front-runner Donald Trump has made immigration a signature issue, vowing to block illegal immigration from Mexico and deport all immigrants who are in the country without documentation, but also proposing measures to reduce legal immigration, including a cutback in the H1-B visas widely used by technology companies to bring in foreign job candidates.

Some other GOP candidates also have called for cutbacks in legal immigration, at least until the wages of average workers begin to rise. Former Florida Gov. Jeb Bush has opposed such ideas, saying legal immigrants are key to raising the economic growth rate.

The subject, which used to divide both parties, has become more sharply partisan in recent years. Since 2002, the share of Democrats who see immigrants, legal and illegal, as a major problem for the country has declined, according to polls, but the percentage among Republicans has remained high. A survey by the Chicago Council on Global Affairs, for example, found that almost two-thirds of Republicans saw "large numbers of immigrants and refugees coming into the U.S." as a "critical threat" to the country. Among Democrats, slightly more than 1 in 4 took that position.

The Census Bureau's data include all foreign-born people in the U.S. without regard to their legal status. But since studies by Pew Research suggest that the population of immigrants here has flattened in recent years, illegal immigration probably had little to do with last year's overall increase.

Much more likely, experts say, is that more foreign-born people — many with advanced degrees as well as those with less education — arrived in the U.S. or decided to stay in the country longer, seeing greater opportunities in an American economy that generated more than 3 million jobs in 2014.