The bad economy and stepped-up federal immigration audits have dramatically slowed the influx of illegal immigrants, experts say.
Demographers, government officials and business leaders say illegal immigrants not only are returning to their homelands in response to more intense government scrutiny, they're also staying there.
And as word spreads that jobs are harder to come by in the United States because of the recession, others are deciding not to come in the first place, slowing an unprecedented flood of immigrants that's lasted more than a decade.
U.S. employers, meanwhile, are hiring fewer undocumented immigrants because they have a bigger pool of unemployed legal workers to choose from and because they fear tighter immigration laws, immigrants and experts say.
"When you start taking away the work force by cracking down on illegal immigration, it scares the bejesus out of employers," said Mark Reed, a former immigration official who once oversaw such measures. "Their mentality changes."
In the San Joaquin Valley, the effect is most noticeable on the west side, where water shortages have aggravated the effects of recession and increased immigration enforcement.
Joseph Riofrio, a Mendota City Council member, said hard times have forced some of the fieldworkers who frequent his small grocery store to return to Mexico, Guatemala, El Salvador and other Latin American countries.
"They say they can eat frijoles y nopales (beans and cactus) here," Riofrio said, "or they can eat them at home in Mexico rather than put up with what's happening here."
Manuel Cunha Jr., president of the Nisei Farmers League in Fresno, said many farmworkers have left to seek work in other farming areas where more water is available, such as the Salinas Valley and Imperial Valley.
But others have simply returned to Mexico, he said.
"I've talked to a lot of folks in the fields who said their friends have gone back home because there's no more work here," Cunha said. "Even in the last two months, there are guys who were thinning fruit on the trees who by now have gone back to Mexico."
12M illegal entrants remain
The estimated 12 million immigrants believed to be living in the country illegally have by no means disappeared from the ranks of the U.S. work force. In the past decade, the population skyrocketed 40 percent.
However, the dramatic year-after-year increases in the population have stalled. The Pew Hispanic Center, which regularly estimates undocumented immigrants in the United States, concluded in its most recent report that the growth in their population began slowing in 2006, a full year before the recession hit.
Roughly 300,000 fewer immigrants came to the country each year from 2005 through 2008, an annual drop of almost 40 percent, according to the center.
As the recession deepened in 2009 and into 2010, the numbers likely continued to decline, said Jeff Passel, a senior demographer with the center, which is preparing an update of its report.
The shift comes at a time when the Obama administration is trying to demonstrate that it is tough on illegal immigration while reassuring the president's political base that he'll eventually pursue a comprehensive immigration overhaul.
States getting involved
Further polarizing the issue, state and local lawmakers, who once left immigration enforcement to the federal government, have stepped in. In 2009, states enacted 222 immigration laws, according to the National Conference of State Legislatures.