Four years ago, I was reporting from the southern U.S. border when construction on the border wall was abruptly halted overnight after former President Joe Biden took office. Now, with President Donald Trump starting a second term, I headed back to the Arizona-Mexico border to report on what’s happening at ground zero under Trump 2.0. As dark fell, I was with Deputy Dan Brennan of the Criminal Interdiction Team in Cochise County, Arizona, when he spotted a rental car from Oregon with travel history – documented through an elaborate tracking system – that seemed suspicious. It turned out to be...