There is no question that Mexico is the main source of illegal or undocumented immigrants, and President Donald Trump says they "present a significant threat to national security and public safety."
But Trump's call for an urgent crackdown raises questions about how serious the problem is.
Just how many, and from where?
About 11.1 million illegal immigrants live in the United States, according to the Pew Research Center, out of a total US population of 324.6 million. That's down from 12.2 million in 2007, just before the Great Recession, due to tougher enforcement and changing economic conditions. About 5.9 million are from Mexico, 700,000 from El Salvador, 525,000 from Guatemala, and 350,000 from Honduras.
Are they all recent arrivals?
No. Two-thirds have been in the country more than ten years, and 86 percent more than five years. Many have settled down with steady jobs and families.
FILE: Rex Tillerson and Luis Videgaray shake hands at a press conference in Mexico City about Washington's plans to crack down on illegal immigration Source: AAP
Do they take American jobs?
Certainly immigrants take jobs, but with the US unemployment rate down to 4.8 percent, the size of the illegal immigrant population does not appear to be preventing native Americans from finding work.
What is the problem, then?
Border security has tightened up and the number of illegal immigrants has been steady for several years. But US officials say just holding that line is a heavy burden. The Department of Homeland Security says that the number of apprehensions of border crossers, "has significantly strained DHS resources."
In fiscal 2016, which ended September 30, the Border Patrol and the Immigration and Customs Enforcement agencies detained about 530,000 people and expelled 451,000.
Meanwhile there are some 534,0000 immigration court cases pending around the country, more than double two years ago.
President Trump says illegal immigrants are a particular source of crime. Is that true?
As a whole, no. According to researcher Alex Nowrasteh at the Cato Institute, data shows that "immigrants are less crime-prone than natives, or have no effect on crime rates." First, he explained, immigrants who are criminals can be deported, and that poses a stronger deterrent to breaking the law than native Americans might face. Secondly, it is possible that many illegal immigrants, motivated to come to the country for economic reasons, are less likely to be criminals.
