But what will that be? Why now? And who are all these immigrants, once you get past the big round numbers?
A big dose of facts, figures and other information to help understand the current debate over immigration:
Major problems with U.S. immigration have been around for decades.
President George W. Bush tried to change the system and failed. President Barack Obama promised to overhaul it in his first term but never did.
In his second term, he's making immigration a priority, and Republicans also appear ready to deal.
Why the new commitment?
Obama won 71 percent of Hispanic voters in his 2012 re-election campaign, and he owes them. Last year's election also sent a loud message to Republicans that they can't ignore this pivotal voting bloc.
It's been the kind of breathtaking turnaround you rarely see in politics. Plus, there's growing pressure from business leaders, who want to make it easier for the U.S. to attract highly educated immigrants and to legally bring in more lower-skilled workers such as farm laborers.
WHAT'S THE PROBLEM?
Talk about "comprehensive immigration reform" generally centers on four main questions:
—What to do about the 11 million-plus immigrants who live in the U.
—How to tighten border security.
—How to keep businesses from employing people who are in the U.S. illegally.
—How to improve the legal immigration system, now so convoluted that the adjective "Byzantine" pops up all too frequently.
WHAT'S THE GANG OF EIGHT?
A group of four Democrats and four Republicans in the Senate, taking the lead in trying to craft legislation that would address all four questions.
Obama is preparing his own plan as a backup in case congressional talks fail. There's also a bipartisan House group working on draft legislation, but House Republican leaders may leave it to the Senate to make the first move.
COMING TO AMERICA
A record 40.4 million immigrants live in the U.S., representing 13 percent of the population. More than 18 million are naturalized citizens, 11 million are legal permanent or temporary residents, and more than 11 million are in the country without legal permission, according to the Pew Hispanic Center, a private research organization.
Those in the U.S. illegally made up about 3.7 percent of the U.S. population in 2010. While overall immigration has steadily grown, the number of immigrants in the U.S. illegally peaked at 12 million in 2007.
WE'RE NO. 1
The U.S. is the leading destination for immigrants. Russia's second, with 12.3 million, according to Pew.
Twenty-nine percent of the foreign-born in the U.S., or about 11.7 million people, came from Mexico. About 25 percent came from South and East Asia, 9 percent from the Caribbean, 8 percent from Central America, 7 percent South America, 4 percent the Middle East and the rest from elsewhere.
The figures are more lopsided for immigrants living here illegally: An estimated 58 percent are from Mexico. The next closest figure is 6 percent from El Salvador, says the government.
California has the largest share of the U.S. immigrant population, 27 percent, followed by New York, New Jersey, Florida, Nevada, Hawaii and Texas, according to the Migration Policy Institute, a private group focused on global immigration issues.
California has the largest share of immigrants in the U.S. illegally, at 25 percent, followed by Texas with 16 percent. Florida and New York each has 6 percent, and Georgia has 5 percent, according to the Department of Homeland Security.
Here's one way to think about the ways immigrants arrive in the U.S: Some come in the front door, others the side door and still others the back door, as laid out in a report from the private Population Reference Bureau.
—Arriving through the front door: people legally sponsored by their families or employers. Also refugees and asylum-seekers, and immigrants who win visas in an annual "diversity" lottery.
—Side door: legal temporary arrivals, including those who get visas to visit, work or study. There are dozens of types of nonimmigrant visas, available to people ranging from business visitors to foreign athletes and entertainers. Visitors from dozens of countries don't even need visas.
—Back door: Somewhat more than half of those in the U.S. illegally have come in the back door, evading border controls, Pew estimates. The rest legally entered, but didn't leave when they were supposed to or otherwise violated terms of their visas.
HOW DO WE KNOW?
It's widely accepted that there are more than 11 million immigrants in the U.S. illegally.
But how do we know that?
Those who are living here without permission typically aren't eager to volunteer that information. Number-crunchers dig into census data and other government surveys, make some educated assumptions, adjust for people who may be left out, mix in population information from Mexico and tend to arrive at similar figures.
The Department of Homeland Security estimates there were 11.5 million immigrants living in the U.S. illegally in January 2011. Pew puts the number at 11.1 million as of March 2011.
Demographers use what's called the "residual" method to get their tally. They take estimates of the legal foreign-born population and subtract that number from the total foreign-born population. The remainder represents those who are living in the country without legal permission.
IS IT A CRIME?
Simply being in the United States in violation of immigration laws isn't, by itself, a crime; it's a civil violation.
Entering the country without permission is a misdemeanor criminal offense. Re-entering the country without authorization after being formally removed can be felony.
Pew estimates that a little less than half of immigrants who lack legal permission to live in the U.S. didn't enter the country illegally. They overstayed their visas, worked without authorization, dropped out of school or otherwise violated the conditions of their visas.
WHAT'S IN A NAME?
There are varying and strong opinions about how best to refer to the 11 million-plus people who are in the U.S. without legal permission.
The last has generally fallen out of favor. Some immigrant advocates are pressing a "Drop the I-Word" campaign, arguing that it is dehumanizing to refer to people as "illegal."
"Undocumented worker" often isn't accurate because many aren't workers, and some have documents from other countries. Homeland Security reports refer to "unauthorized immigrants," but the agency also reports statistics on "aliens apprehended."
—Legal permanent residents (LPRs): people who have permission to live in the U.S. permanently but aren't citizens. They're also known as "green card" holders. Most of them can apply for citizenship within five years of getting green cards. In 2011, 1.06 million people got the cards.
—Refugees and asylees: people who come to the U.S. to avoid persecution in their home countries. What's the difference between the two terms? Refugees are people who apply for protective status before they get to the U.S. Asylees are people who apply upon arrival in the U.S. or later.
—Naturalization: The process by which immigrants become U.S. citizens.
Is there an actual green card? Indeed there is.
It's the Permanent Resident Card issued to people who are authorized to live and work in the U.S. on a permanent basis. In 2010, the government redesigned them to add new security features—and make them green again.
The cards had been a variety of colors over the years. New green cards are good for 10 years for lawful permanent residents and two years for conditional residents.
PATH TO CITIZENSHIP
There's a lot of talk about creating a "path to citizenship" for immigrants who are in the U.S. without legal status. But there's no consensus on what the route should be, and some conservatives reject the idea outright, seeing it as tantamount to amnesty.
There is a vigorous debate over what conditions immigrants who are in the U.S. illegally should have to satisfy to get citizenship—paying taxes or fees, passing background checks, etc.
Some Republicans want to first see improvements in border security and in tracking whether legal immigrants leave the country when required. Obama doesn't support linking the path to citizenship with border security.
Some conservatives want to grant immigrants who are in the U.S. illegally some sort of legal status that stops short of citizenship. Some 43 percent of Americans think those who are here illegally should be eligible for citizenship, one-quarter think they should only be allowed to apply for legal residency, and about the same share think they should not be allowed to stay legally at all, according to a Pew Research Center survey released in March.
A NEW ACRONYM
Move over LPRs; make way for LPIs.
The president's draft immigration proposal would create a "Lawful Prospective Immigrant" visa. It would allow those who are here illegally to become legal permanent residents within eight years if they met certain requirements such as a criminal background check. They could later be eligible to become U.S. citizens.
Nothing stirs up a hornet's nest like talk of amnesty for immigrants who are in the country illegally, although there's a lot of disagreement over how to define the term.
A 2007 effort to overhaul the immigration system, led by Bush, failed in part because Republicans were dismayed that it included a process to give otherwise law-abiding immigrants who were in the country illegally a chance to become citizens. Critics complained that would be offering amnesty.
All sides know it's not practical to talk about sending 11 million-plus people back to their countries of origin. So one big challenge this time is finding an acceptable way to resolve the status of those who are in the country illegally.
GETTING A REPRIEVE
While the larger immigration debate goes on, the government already is offering as many as 1.76 million immigrants who are in the country illegally a way to avoid deportation, at least for now.
Obama announced a program in June that puts off deportation for many people brought here as children. Applicants for the reprieve must have arrived before they turned 16, be younger than 31 now, be high school graduates or in school, or have served in the military. They can't have a serious criminal record or pose a threat to public safety or national security.
Applications for the Deferred Action for Childhood Arrivals program are averaging 3,300 a day. By mid-March, nearly 454,000 people had applied and more than 245,000 had been approved, with most of the rest still under consideration.
In some ways, the program closely tracks the failed DREAM Act, which would have given many young illegal immigrants a path to legal status. Obama's program doesn't give them legal status but it at least protects them from deportation for two years.
HISTORY: DOING THE WAVE
The U.S. is in its fourth and largest immigration wave.
First came the Colonial era, then an 1820-1870 influx of newcomers mostly from Northern and Western Europe. Most were Germans and Irish, but the gold rush and jobs on the transcontinental railroad also attracted Chinese immigrants.
In the 1870s, immigration declined due to economic problems and restrictive legislation.
The third wave, between 1881 and 1920, brought more than 23 million people to the U.S., mostly from Southern and Eastern Europe, aided by cheaper trans-Atlantic travel and lured by employers seeking workers.
Then came the Great Depression and more restrictive immigration laws, and immigration went into decline for decades.
The fourth wave, still underway, began in 1965 with the end of immigration limits based on nationality. Foreign-born people made up 1 in 20 residents of the U.S. in 1960; today, the figure is about 1 in 8.
HISTORY: HERE A LAW, THERE A LAW
Until the late 1800s, immigration was largely a free for all. Then came country-by-country limits. Since then, big changes in U.S. immigration law have helped produce big shifts in migration patterns.
Among the more notable laws:
—1965 Immigration and Nationality Act: Abolished country-by-country limits, established a new system that determined immigration preference based on family relationships and needed skills, and expanded the categories of family members who could enter without numerical limits.
—1986 Immigration Reform and Control Act: Legalized about 2.7 million immigrants living in the U.S. illegally, 84 percent of them from Mexico and Central America.
—1990 Immigration Act: Increased worldwide immigration limit to a "flexible cap" of 675,000 a year. The number can go higher in some years if there are unused visas available from the previous year.
—1996 Immigrant Reform and Immigrant Responsibility Act. Expanded possible reasons for deporting people or ruling them ineligible to enter the U.S., expedited removal procedures, gave state and local police power to enforce immigration laws.
—Post-2001: In 2001, talk percolated about a new immigration plan to deal with unauthorized immigrants, guest workers and violence along the Mexican border. But the Sept. 11 terrorist attacks of 2001 put an end to that, amid growing unease over illegal immigration.
ABOUT LAST TIME. ...
The last big immigration legalization plan, in 1986, took six years to get done.
The law, signed by President Ronald Reagan, had three main components: making it illegal to hire unauthorized workers, improving border enforcement and providing for the legalization of a big chunk of the estimated 3 million to 5 million immigrants then in the country illegally.
The results were disappointing on two central fronts: The hiring crackdown largely failed because there was no good way to verify eligibility to work, and it took a decade to improve border security. As a result, illegal immigration continued to grow, fueled by the strong U.S. economy.
What did work as intended: Close to 3 million immigrants living in the U.S. without permission received legal status. By 2009, about 40 percent of them had been naturalized, according to Homeland Security.
Census figures show that between 1960 and 2010, immigration from Europe declined while the numbers coming from Latin America and Asia took off. As the immigrants' points of origin changed, so did their destinations. Concentrations shifted from the Northeast and Midwest to the South and West.
A few Census Bureau snapshots:
—In 1960, there were fewer than 1 million people in the U.S. who were born in Latin America. By 2010, there were 21.2 million.
—In 1960, 75 percent of foreigners in the U.S. came from Europe. By 2010, 80 percent came from Latin America and Asia.
—In 1960: 47 percent of the foreign-born lived in the Northeast and 10 percent in the South. By 2010, 22 percent lived in the Northeast and 32 percent in the South.
The fence between the U.S. and Mexico runs off and on for 651 miles along the 1,954-mile border. Most of it has been built since 2005. At some points, it's an 18-foot-high steel mesh structure topped with razor wire. At others, it's a rusting, 8-foot-high thing, made of Army surplus landing mats from the Vietnam War.
The fencing is one of the more visible manifestations of a massive effort over the past two decades to improve border security. The results of that effort are dramatic. Those images of crowds of immigrants sprinting across the border illegally while agents scramble to nab a few are largely a thing of the past.
Two decades ago, fewer than 4,000 Border Patrol agents worked along the Southwest border. Today there are 18,500.
Plummeting apprehension statistics are one measure of change: 357,000 last year, compared with 1.6 million in 2000. The numbers are down in part because fewer are trying to make it across.
The border isn't sealed but it is certainly more secure.
WHO'S HANGING AROUND
With tighter border security and years of economic difficulty in the U.S., it turns out that most of the immigrants who are in the U.S. without permission have been there for a while. Just 14 percent have arrived since the start of 2005, according to Homeland Security estimates. In contrast, 29 percent came during the previous five years.
At the peak in 2000, about 770,000 immigrants arrived annually from Mexico, most of them entering the country illegally. By 2010, the pace had dropped to about 140,000, most of them arriving as legal immigrants, according to Pew.
Mexicans, mostly. Since 1986, more than 4 million noncitizens have been deported. Deportations have expanded in the Obama administration, reaching 410,000 in 2012 from 30,000 in 1990. Most of those deported—75 percent—are sent back to Mexico. Nearly half of those removed had prior criminal convictions. So far, the Obama administration has deported more than 1.6 million people.
TO NATURALIZE OR NOT
Lots of U.S. immigrants who are eligible to become naturalized citizens don't bother. As of 2010, about two-thirds of eligible immigrants had applied for citizenship, according to the Migration Policy Institute. That lags behind the rate in other English-speaking countries such as Australia and Canada, which do more to promote naturalization.
What's so great about citizenship?
Naturalization offers all sorts of rights and benefits, including the right to vote and run for office. Naturalized citizens are protected from losing their residency rights and being deported if they get in legal trouble. They can bring family members into the U.S. more quickly.
Certain government jobs and licensed professions require citizenship. Citizenship also symbolizes full membership in U.S. society.
In 2010, there was a 67 percent earnings gap between naturalized citizens and noncitizen immigrants, according to a report from the Migration Policy Institute. Even after stripping out differences in education, language skills and work experience, naturalized citizens earned at least 5 percent more.
Nearly two-thirds of the 5.4 million legal immigrants from Mexico who are eligible to become U.S. citizens haven't done so, according to a Pew study released in February. Their rate of naturalization is half that of legal immigrants from all other countries combined. The barriers to naturalization cited by Mexican nonapplicants include the need to learn English, the difficulty of the citizenship exam and the $680 application fee.
How do immigrants who are in the U.S. without permission fit into the nation's jobs picture?
In 2010, about 8 million were working in the U.S. or trying to get work. They made up about 5 percent of the labor force, according to Pew. Among U.S. farm workers, about half are believed to be in the country illegally, according to the Government Accountability Office.
Business groups want a system to legally bring in both more highly skilled workers and more lower-skilled workers such as agricultural laborers. The idea is to hire more when Americans aren't available to fill jobs. This has been a sticking point in past attempts at immigration overhaul. Labor groups want any such revamped system to provide worker protections and guard against displacing American workers. Current temporary worker programs are cumbersome and outdated.
Current law requires employers to have their workers fill out a form that declares them authorized to work in the U.S. Then the employer needs to verify that the worker's identifying documents look real. But the law allows lots of different documents, and many of them are easy to counterfeit.
The government has developed a mostly voluntary employment verification system called E-Verify, which has gradually gotten better. But so far just 10 percent of employers are using it, according to the Migration Policy Institute. The system is now required in varying degrees by 19 states.
FAMILIES VS. JOBS
A big question in the immigration debate centers on how much priority to give to the family members of U.S. citizens and permanent residents.
Under current law, the U.S. awards a much larger proportion of green cards to family members than to foreigners with job prospects here. About two-thirds of permanent legal immigration to the U.S. is family-based, compared with about 15 percent that is employment-based, according to the Migration Policy Institute. The rest is largely humanitarian.
Some policymakers think employment-based immigration should be boosted to help the economy. Advocates for families want to make sure any such action doesn't come at the expense of people seeking to join relatives in the U.S.
For all the attention being devoted to immigration right now, it's not the top priority for most people, even for most Hispanics. It ranked 17th on a list of policy priorities in a recent Pew Research Center poll. Among Hispanics, one-third said immigration was an extremely important issue to them, behind such issues as the economy and jobs, education and health care.
WHAT TO DO?
The public is divided on what should be done to fix immigration problems. In a recent Pew survey, 28 percent said the priority should be tighter restrictions on immigration, 27 percent said creating a path to citizenship, and 42 percent thought both approaches should get equal priority.
A VIEW FROM THE SOUTH
Is life actually better in the U.S.? A little more than half of Mexican adults think so, according to a 2012 Pew Global Attitudes poll. Thirty-eight percent said they'd move to the U.S. if they had the chance. Nineteen percent said they'd come even without authorization.
Sources: Pew Hispanic Center, Migration Policy Institute, Department of Homeland Security, Census Bureau, Government Accountability Office, Population Reference Bureau, Encyclopedia of Immigration.
Associated Press writers Alicia Caldwell and Erica Werner contributed to this report.
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