Trump visits U.S.-Mexico border

Donald Trump poses with policemen, as he departs Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

Donald Trump arrives on his signature plane in Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

Donald Trump waves as he departs Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

A long line of semi-trucks leave Mexico and enter the U.S. near where Donald Trump spoke, outside Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

Donald Trump is pictured at a news conference near the U.S.-Mexico border outside of Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

A protester stands outside the airport, awaiting the arrival of Donald Trump, in Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

Protesters gather outside the airport, awaiting the arrival of Donald Trump, in Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

Donald Trump gestures at a news conference near the U.S.- Mexico border (background) outside of Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

Donald Trump talks to reporters as he arrives in Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

A protester is interviewed outside the airport as he awaits the arrival of Donald Trump, in Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

The motorcade carrying Donald Trump arrives near the U.S.-Mexico border, outside Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

Donald Trump gestures at a news conference near the U.S.- Mexico border outside of Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

Donald Trump gestures during a news conference near the U.S.-Mexico border, outside of Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

Donald Trump talks to reporters as he arrives in Laredo, Texas July 23, 2015. REUTERS/Rick Wilking

Donald Trump gestures as he leaves Laredo, Texas July 23, 2015. REUTERS/Rick Wilking