The numbers behind President Obama’s immigration overhaul by Tom Huddleston, Jr. @FortuneMagazine November 20, 2014, 7:55 PM EST E-mail Tweet Facebook Google Plus Linkedin Share icons President Obama raised a touchy subject Thursday night when he unveiled his plan to grant temporary legal status and work permits to nearly 5 million unauthorized immigrants. He’s already facing stiff opposition by Republicans who argue that his plan sends the wrong message to undocumented migrants and, in fact, encourages more people without the proper paperwork to enter the country. Understanding the issue of illegal immigration depends a lot on knowing the number of people involved. It’s complex calculation with many nuances. Here are some key points related to immigration in the U.S., courtesy of the Pew Research Center, a non-partisan organization that collects data about a number of issues: How many affected?: Pew estimates there are about 11.3 million unauthorized immigrants currently in the U.S. About 3.5 million of them are parents to U.S.-born children who have lived in the country for at least five years and there are 2.8 million parents whose U.S.-born children have lived here for at least 10 years. In his speech, Obama said that his plan would grant new legal status to more than 4 million undocumented immigrants whose children are U.S. citizens or legal permanent residents, assuming they meet certain requirements. Children: Pew reports that there are roughly 650,000 people under the age of 18 who came to the U.S. illegally as children and are not currently protected from the possibility of deportation. Labor Force: Illegal immigrants currently make up about 5.1% of the U.S. labor force. Those working or looking for work total 8.1 million people, and the number has remained between 8.1 million and 8.3 million since 2007. Temporary Protection: Roughly 1 million immigrants are at least temporarily safe from deportation under the Department of Homeland Security’s Deferred Action for Childhood Arrivals program — which applies to people between the ages of 15 or 30 who were brought to the U.S. illegally as children — or they have been granted Temporary Protected Status by the U.S. Citizenship and Immigration Services. Obama’s Deportations: The U.S. government deported a record 438,421 illegal immigrants in 2013 and more than 400,000 immigrants a year have been deported on average since 2009. Compared to Bush: Under Obama’s predecessor, President George W. Bush, an average of 252,000 immigrants were deported each year, including 360,000 in Bush’s last year in office. Polls: Last month, a Pew survey found that 71% of Americans favored offering unauthorized immigrants a pathway to citizenship. As Time notes, Ronald Reagan was the last president to grant legal status to such a large number of undocumented immigrants. In 1986, Reagan signed a bill offering a path to citizenship for roughly 3 million people.