Democrats are converting their emotional protests against “family separation” into unpopular calls for the catch-and-release of many Central American migrants into ordinary Americans’ jobsites and schools. The pre-election, pro-migration push is a huge risk, according to a poll by The Economist and YouGov which shows 3:1 public opposition to the Democrats’s catch-and-release policy. That opposition to catch-and-release was reinforced by President Donald Trump’s June 20 Executive Order to keep families together in detention until their appeal is decided by a judge. Many Democrats are pushing their demand that migrants caught at the border be quickly released into Americans’ workplaces and...