French riot policemen force out migrants who were hidden in a truck that was making its way to the ferry terminal in Calais in western France on Wednesday. The cross-Channel port has become the last barrier for economic and political migrants trying to enter Britain illegally. Pascal Rossignol/Reuters/Landov hide caption

itoggle caption Pascal Rossignol/Reuters/Landov

A slide of migratory flows in the Mediterranean Sea from the Mare Nostrum operation is displayed in the control room of the Italian operation, which tracks and intercepts migrant ships en route to Europe. Sylvia Poggioli/NPR hide caption

itoggle caption Sylvia Poggioli/NPR

Nora Sandigo sits with Ronald Soza and his sister Cecia in 2009, while the children were on a hunger strike to protest the deportation of their mother. Sandigo is the legal guardian of the Soza children (now 15 and 18) — and 815 other American children of undocumented immigrants. Lynne Sladky/AP hide caption

itoggle caption Lynne Sladky/AP

The U.N. is encouraging the U.S., Mexico and other countries to treat migrant children as refugees, on the grounds that they're fleeing danger. Last week, immigration activists demanded that Mexico protect the rights of minors and families crossing its territory, during a protest outside the Mexican Consulate in Los Angeles. Damian Dovarganes/AP hide caption

itoggle caption Damian Dovarganes/AP

Human-rights activist Enrique Morones, at podium, speaks during a rally in support of immigrants on Wednesday in San Diego. A group of about 70 people rallied in support of migrant children and families Wednesday, a day after U.S. Homeland Security buses carrying the migrants were routed away from American flag-waving protesters in Murrieta, Calif., and transported to a facility in San Diego. Gregory Bull/AP hide caption

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A migrant from El Salvador holds a map he received from church workers at the Mexico-Guatemala border. It shows the freight train schedules and routes to the U.S. border. Carrie Kahn/NPR hide caption

itoggle caption Carrie Kahn/NPR

Migrants arrive at a rest stop in Ixtepec, Mexico, after a 15-hour ride atop a freight train headed north toward the U.S. border on Aug. 4. Thousands of migrants ride atop the trains, known as La Bestia, or The Beast, during their long and perilous journey through Mexico to the U.S. John Moore/Getty Images hide caption

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GOP leadership decided against keeping an immigration-related provision in the defense authorization bill. But it allowed one banning the Defense Department from participating in climate change research. Carolyn Kaster/AP hide caption

itoggle caption Carolyn Kaster/AP

Migrants arrive in Valletta, the Maltese capital, aboard a patrol boat on Oct. 12, a day after their boat sank, killing more than 30 people, mostly women and children — just the latest deadly migrant tragedy to hit the Mediterranean. Despite Europe's financial crisis illegal immigrants continue to attempt to enter Europe through its southern coastal countries as they seek a better life. AFP/Getty Images hide caption

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Sen. Marco Rubio, R-Fla., says talk of a bipartisan agreement among eight key senators working on immigration law is "premature." Susan Walsh/AP hide caption

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A woman takes the oath of allegiance during a naturalization ceremony at the district office of the U.S. Citizenship and Immigration Services in Newark, N.J. John Moore/Getty Images hide caption

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