Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Presidential Candidates' Differing Positions on Immigration by Liliana Henao Comprehensive immigration reform, more border security and self-deportation are some of the terms used when talking about the controversial issue of illegal immigration in the United States. With the clock ticking until the next presidential election, both candidates have to clarify their specific plans to bring an estimated 11 million of undocumented immigrants out of the shadows. They sparred about it in their second debate, but while President Barack Obama and his Republican opponent, Mitt Romney, believe the U.S. immigration system must be reformed, they don't agree on how to achieve that. "I will not grant amnesty to those who've come here illegally, what I will do is I'll put in place an employment verification system and make sure that employers that hire people who have come here illegally are sanctioned for doing so," said Romney. Katherine Vargas, Director of Communications with the National Immigration Forum, says the Republican candidate has not been specific.