“Until the 1990s, border crossing was almost always treated as a civil offense, punishable by deportation. But in the late 1980s, Congress started to change that. By 1996, crossing the border after deportation was punishable by years of imprisonment, with enhanced sentences for people previously convicted of crimes—most often drug offenses. Though federal investigators have found no evidence that criminalization has reduced the pace of border crossings over the long term, prosecutions for illegal entry and re-entry rose from fewer than 4,000 a year at the start of Bill Clinton’s presidency, to 31,000 in 2004 under George W. Bush, to a high of 91,000 in 2013 under President Obama.”