Illegal border crossings fell to their lowest level in at least five years in 2017, but after plunging through April, the numbers have risen each of the past eight months, according to U.S. Customs and Border Protection (CBP). Meanwhile, the debate continues: Build a physical wall spanning from the Gulf of Mexico to the Pacific Ocean, add more Border Patrol agents or combine better physical barriers with technology to stop drug trafficking, smuggling and illegal immigration?