People stand at the border fence between Mexico and the U.S. in Tijuana February 25, 2013. How effective U.S. border security is in stopping illegal immigration will be vital to convincing mostly Republicans to back the bipartisan reform and accept some of its more ambitious parts, such as creating a path to citizenship for the estimated 11 million illegal immigrants living in the United States. Picture taken February 25, 2013. To match Feature USA-IMMIGRATION/MEXICO REUTERS/Jorge Duenes (MEXICO - Tags: SOCIETY IMMIGRATION POLITICS) 

A man walks on the beach near the border fence between Mexico and the U.S., in Tijuana March 20, 2013. How effective U.S. border security is in stopping illegal immigration will be vital to convincing mostly Republicans to back the bipartisan reform and accept some of its more ambitious parts, such as creating a path to citizenship for the estimated 11 million illegal immigrants living in the United States. To match Feature USA-IMMIGRATION/MEXICO REUTERS/Jorge Duenes (MEXICO - Tags: SOCIETY IMMIGRATION POLITICS) 

People stand near the border fence between Mexico and the U.S. in Tijuana February 25, 2013. How effective U.S. border security is in stopping illegal immigration will be vital to convincing mostly Republicans to back the bipartisan reform and accept some of its more ambitious parts, such as creating a path to citizenship for the estimated 11 million illegal immigrants living in the United States. Picture taken February 25, 2013. To match Feature USA-IMMIGRATION/MEXICO REUTERS/Jorge Duenes (MEXICO - Tags: SOCIETY IMMIGRATION POLITICS) 

A couple stands at the border fence between Mexico and the U.S. in Tijuana February 25, 2013. How effective U.S. border security is in stopping illegal immigration will be vital to convincing mostly Republicans to back the bipartisan reform and accept some of its more ambitious parts, such as creating a path to citizenship for the estimated 11 million illegal immigrants living in the United States. Picture taken February 25, 2013. To match Feature USA-IMMIGRATION/MEXICO REUTERS/Jorge Duenes (MEXICO - Tags: SOCIETY IMMIGRATION POLITICS) 

A U.S. border patrol parks near the border fence between Mexico and the U.S. as seen from Tijuana February 25, 2013. How effective U.S. border security is in stopping illegal immigration will be vital to convincing mostly Republicans to back the bipartisan reform and accept some of its more ambitious parts, such as creating a path to citizenship for the estimated 11 million illegal immigrants living in the United States. Picture taken February 25, 2013. To match Feature USA-IMMIGRATION/MEXICO REUTERS/Jorge Duenes (MEXICO - Tags: SOCIETY IMMIGRATION POLITICS) 

Mexican grandmother Lucia Angulo stands near the border fence between Mexico and the U.S. in Tijuana February 25, 2013. Angulo has entered the United States illegally so often over the last three decades she has lost count of how many times border patrols caught her. Picture taken February 25, 2013. To match Feature USA-IMMIGRATION/MEXICO REUTERS/Jorge Duenes (MEXICO - Tags: SOCIETY IMMIGRATION POLITICS) 

Mexican grandmother Lucia Angulo stands near the border fence between Mexico and the U.S. in Tijuana February 25, 2013. Angulo has entered the United States illegally so often over the last three decades she has lost count of how many times border patrols caught her. To match Feature USA-IMMIGRATION/MEXICO Picture taken February 25, 2013. REUTERS/Jorge Duenes (MEXICO - Tags: SOCIETY IMMIGRATION POLITICS) 

Mexican Zapatista rebel leader Subcomandante Marcos, also known as the "delegado Zero" speaks during a rally in Mexico's city main square in support of Mexican and Latino migrants in the U.S. May 1, 2006. Thousands of Mexicans marched through the capital and boycotted U.S. stores on Monday to support illegal immigrants demonstrating for more rights in the United States. REUTERS/Daniel Aguilar 

Mexican Zapatista rebel leader Subcomandante Marcos, also known as the "delegado Zero" speaks during a rally in Mexico's city main square in support of Mexican and Latino migrants in the U.S. May 1, 2006. Thousands of Mexicans marched through the capital and boycotted U.S. stores on Monday to support illegal immigrants demonstrating for more rights in the United States. REUTERS/Daniel Aguilar 

Mexican Zapatista rebel leader Subcomandante Marcos, also known as the 'delegado Zero' speaks during a rally in Mexico´s city main square in support of Mexican and Latino migrants in the U.S. May 1, 2006. Thousands of Mexicans marched through the capital and boycotted U.S. stores on Monday to support illegal immigrants demonstrating for more rights in the United States. REUTERS/Daniel Aguilar