Immigration fact check: ‘Who built the cages?’

Women and children sit in a holding cell at a Border Patrol processing center after being detained by agents near the U.S.-Mexico border near McAllen, Texas. One moment that stood out was an extended discussion of the Trump administration’s fraught “zero-tolerance” policy that resulted in the separation of an estimated 4,000 children from their parents at the southern U.S. border. Prior to the debate, news reports surfaced that the federal government still couldn’t find the parents of 545 children separated during a pilot program that predates the “zero-tolerance” policy the Trump administration put into effect in May 2018. During the sharp exchange, which was prompted by a question about the missing children posed by moderator Kristen Welker, Trump and Biden fired allegations at each other about which administration started the family separation process, who “built the cages,” and others. Yes, U.S. border officials did separate children from their parents on occasion, but it was not as widespread or systematic as it became under the Trump administration, particularly during its “zero-tolerance policy,” which was meant to deter migrants from seeking refuge in the U.S. What was the “zero-tolerance” policy?