Illegal immigrant population falls below 11 million in U.S.

WASHINGTON — The illegal immigrant population in the United States has fallen below 11 million, continuing a nearly decade-long decline that has the potential to reshape the debate over reforming the nation’s immigration system, according to a study released Wednesday.

The total undocumented immigrant population of 10.9 million is the lowest since 2003, says the report from the Center for Migration Studies, a New York think tank. The number of undocumented immigrants has fallen each year since 2008, the report says, driven primarily by a steady decline in illegal migrants from Mexico. Even sharper declines from South America and Europe have contributed to the overall numbers, the report says, even as illegal immigration from Central America — where families with children have flocked across the southwest border in recent months — is on the rise.

Written by Robert Warren, a former longtime U.S. government demographer, the document could have an impact on the fiery debate over immigration that has unfolded on the 2016 presidential campaign trail. Republican candidates, led by Donald Trump, have portrayed the border as overwhelmed by illegal immigrants who must be kept out by a massive wall the New York developer proposes to build. President Barack Obama and Democratic candidates say the border has never been more secure and call for comprehensive immigration reform to naturalize immigrants already here.

While it doesn’t take a political position or name a party, the paper uses 2014 Census Bureau data to essentially argue that the Republican portrayal is inaccurate. “One reason for the high and sustained level of interest in undocumented immigration is the widespread belief that the trend in the undocumented population is ever upward,” the 15-page report says. “This paper shows that this belief is mistaken and that, in fact, the undocumented population has been decreasing for more than a half a decade.”

The debate over how to handle illegal migrants already here has escalated even more in recent weeks. The Obama administration has launched a series of raids aimed at deporting the mostly women and children who have come from Honduras, Guatemala and other Central American countries since 2014. Administration officials are now working frantically to quell political outrage the raids have triggered among immigration rights advocates and Latino leaders.

The new report echoes other research showing that the nation’s illegal immigration flows have fallen to their lowest level in at least two decades. Demographers at Pew Research Center, for example, found last year that the number of illegal immigrants — which more than tripled, to 12.2 million, between 1990 and 2007 — had since dropped by about 1 million. Pew’s preliminary estimate counted the total illegal immigration population at 11.3 million, as of 2014. The new Center for Migration Studies report is the first in recent years to peg the number as falling below 11 million.

Although the new report does not cite specific reasons for the decline, other experts have attributed it to a combination of tighter U.S. border security measures and economic and demographic changes in Mexico, such as women having fewer children.

A key — but largely overlooked — sign of these ebbing flows is the changing makeup of the undocumented population. Until recent years, illegal immigrants tended to be young men streaming across the Southern border in pursuit of work. But demographic data show that the typical illegal immigrant now is much more likely someone who is 35 or older and has lived in the United States for a decade or more.