Lost in the furor over President Obama's executive action on immigration are recent trends that run counter to the common perception that illegal immigration is on a ceaseless climb.
Nationwide, the population of unauthorized immigrants actually leveled off from 2009 to 2012 and remains stable at around 11.2 million, the Pew Research Center, a Washington group, said in a report last week.
Among other findings in the report, titled "Unauthorized Immigrant Totals":
The number of people in the United States illegally fell in 14 states, rose in seven, and in the remainder showed no statistically significant change.
Five of the seven states, including Pennsylvania and New Jersey, where growth occurred are on the East Coast, not in the Southeast or Southwest, which have been the traditional magnets for illegal immigration.
Pennsylvania and New Jersey together had the greatest increase in undocumented residents of any two adjacent states, totaling 105,000 since 2009, said Pew, self-described as a "non-partisan fact tank" that "does not take policy positions."
Experts said the U.S. recession of 2008, the hardening of the border with Mexico, 400,000 deportations a year, and slight improvements in Mexico's economy were factors driving the findings.
"One thing these numbers signal is the continued revitalization of Philadelphia, its suburbs, and other regions of the Northeast," said Domenic Vitiello, a University of Pennsylvania associate professor of city planning and urban studies with expertise in immigration.
"As the Northeast suffered less from the Great Recession and rebounded more and more quickly than many metro regions in the Southwest and Southeast, jobs in restaurants, construction, housekeeping, and other sectors where unauthorized immigrants commonly work have been sustained or experienced growth," Vitiello said.
David Dyssegaard Kallick, director of immigration research for the Fiscal Policy Institute, a New York nonprofit that examines the role of immigrants in New York state and beyond, said: "It adds up to what I think is now established as a pretty clear trend, if you can call a flat line a trend."
In the parts of the country where growth in unauthorized immigration occurred, Pew said, it was driven by increased illegal immigration from countries other than Mexico.
In Pennsylvania, where people here illegally make up 1.3 percent of the state population, the top three countries of birth for unauthorized immigrants are Mexico, India, and the Dominican Republic.
In New Jersey, where undocumented immigrants are 5.8 percent of the population, the top three are Mexico, India, and Ecuador.
"The center of gravity of immigration has been moving steadily away from California to along the Eastern Seaboard," said Princeton University professor of sociology Douglas Massey, an expert on migration.
When the Southwest got hit hard by the recession, it lost many of the residential construction jobs that sustain unauthorized immigrants, Massey said. "The Northeast got hit hard," he said, "but not to the same extent."
Though defenders of Obama's executive action find support for it in the Pew study, the report offers rhetorical ammunition for immigration restrictionists, too.
From 1990 to 2007, it states, the population of undocumented immigrants increased "from 3.5 million to 12.2 million, growth of about 250 percent, or an average of more than 500,000 people a year."
"So basically a very bad situation is now just bad?" said Steven Camarota, director of research at the Center for Immigration Studies, a Washington group that favors limited immigration.
"That's like continually running a huge debt, which hasn't gotten worse. But that doesn't mean you've solved your financial problems."
Read the Pew report by clicking here.