Donald Trump speaks to the media at the U.S.-Mexico border in July. The Libre Initiative's letter doesn't call out any candidates by name, but Trump has called for mass deportation and an end to birthright citizenship for immigrants. LM Otero/AP hide caption

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Donald Trump arrives at the National Federation of Republican Assemblies on Saturday in Nashville, Tenn., ahead of his speech before the conservative group. Mark Humphrey/AP hide caption

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All the talk about immigration in the U.S. presidential campaign has renewed focus on the linguistic question of how to refer to people from Latin America. Here, the flags of Latin American and Caribbean states fly at a regional summit in San Jose, Costa Rica, in January. Arnoldo Robert/LatinContent/Getty Images hide caption

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Republican presidential candidate Donald Trump speaks at a press conference Wednesday prior to a town hall meeting at Pinkerton Academy in Derry, N.H. Matthew Healey/UPI/Landov hide caption

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Catching up with a national trend, more Hispanics say they are not affiliated with a particular religion — a shift that could make the gap between Latinos and Republicans even wider. iStockphoto hide caption

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Cristina Saralegui waves at the Democratic National Convention in Charlotte, N.C., on Wednesday. Joe Raedle/Getty Images hide caption

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Rep. Charles Rangel, D-N.Y., participates in last week's National Puerto Rican Day Parade in New York City. Richard Drew/AP hide caption

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