Over the past week, border security has been the biggest sticking point in Senate discussions about immigration reform.
Many Republicans, like Sen. John Cornyn (R-Tex.) have argued that the United States shouldn’t provide a pathway to citizenship for the 11.5 million unauthorized immigrants currently in the country until the U.S. border with Mexico is secure.
But what does it actually mean for that border to be secure? Who decides? And is a completely secure border even possible?