Indeed, Mr. Camarota’s numbers show that most of the immigrant employment growth went to new arrivals, not to foreign-born residents already in the United States — a figure that suggests immigrants already settled here were having some of the same difficulties as the native-born.
There is some bright news: an uptick over the past year among native-born Americans accounting for two-thirds of all new employment growth.
Net immigration — both legal and illegal — averaged more than 1.1 million in the 1990s and slightly less than 900,000 in the past decade.
Mr. Camarota said it didn’t slow much despite the economic downturn.
“We have a situation where the job market — the bottom fell out, yet we kept legal immigration relatively high without even a national debate,” he said. “As a consequence, a lot of the job growth has been going to immigrants.”
Immigration has been a touchy political issue for more than a decade, and while all sides agree that the system is broken, efforts to overhaul it in 2006 and 2007 fell short.
This campaign, Mr. Romney and Mr. Obama have talked about streamlining the legal immigration system to allow in more high-tech workers. Mr. Romney has said he wants to “staple a green card” to every advanced degree in science, mathematics or engineering earned by an immigrant.
Beyond that, Mr. Obama has vowed to make legalizing illegal immigrants a major push in a second term — and has said if he wins re-election, he thinks Republicans will embrace that goal, realizing that otherwise, Hispanic voters will reject the GOP.
Mr. Romney has talked about legalizing a small number of illegal immigrants, though he has been studiously vague about his specific plans in an effort to try not to alienate voters on either side of the issue.
Mr. Obama did take action this year to grant many illegal immigrants up to 30 years of age a tentative legal status that prevents them from being deported and authorizes them to work in the United States.
Some Republicans in Congress have criticized Mr. Obama’s policy, saying it violates his powers and will mean more competition for scarce jobs.
Mr. Romney has said he would not rescind any stays of deportation that Mr. Obama issues but wouldn’t issue any new ones himself.
The current system doles out legal visas based on family ties or employment prospects or even a random lottery designed to increase the diversity of those coming to the United States.
In 2007, senators proposed scrapping the legal system and replacing it with a points-based system that would assign a desirability grade to would-be immigrants. Work skills would have gained under that system.