Progressive Sen. Jeff Merkley (D-Ore.) on Thursday acknowledged that the surge in migrant children coming to the U.S.–Mexico border is “approaching a crisis” that could worsen with an ongoing flow of people from South American countries. When asked by CNN’s Alisyn Camerota if it is “fair to call what we’re seeing today at the border a crisis,” Merkley blamed the Trump administration’s immigration policies that he said created a back-log of children waiting in Mexico. Merkley said that the children coming to the border now were the ones “stranded, some for months, some for years, by the Trump administration in Mexico under completely intolerable circumstances.” “Now that the border is not closed, they’re knocking on our door, and you had a set of policies that were determined to treat children very poorly so you didn’t have essentially the systems in place under the Trump administration, and the Biden administration is creating those systems and they’re doing …