FILE -This March 27, 2013 file photo shows, from left, Sen. Chuck Schumer, D-N.Y., Sen. John McCain, R-Ariz., Sen. Jeff Flake, R-Ariz., and Sen. Michael Bennett, D-Colo., touring the Nogales port of entry on part of their tour of the Mexico border with the United States in Nogales, Ariz. Arizona remained front-and-center in the continuing national debate over immigration in 2013. The states' two senators, John McCain and Jeff Flake, were among the bipartisan "gang of eight" senators promoting a long-awaited immigration overhaul. (AP Photo/Ross D. Franklin, File)