On her first foreign trip as Vice President in June 2021, Kamala Harris was tasked with delivering a blunt message in Guatemala City. "I want to be clear to folks in this region who are thinking about making that dangerous trek to the United States-Mexico border: Do not come," she said at a press conference, pausing for effect. "Do not come." Three years later, that sound bite may come to haunt Harris' nascent presidential campaign. Despite her warning, border crossings reached historic...