Since Joe Biden’s first day in office, when he signed seven executive orders on immigration that, among other things, suspended deportations and ended the Trump administration’s “Remain in Mexico” program that had eased the crush of those awaiting asylum hearings, the president has in word and deed sent signals that migrants have interpreted as welcoming. The initiatives include reviving the Obama-era policy known as “catch and release,” “paroling” illegal border crossers so they can enter the country, resettling migrants through secret flights around the country, and ending the “no match” policy that had helped the government identify people who were using fraudulent credentials to find work.