In 2018 the US government under President Trump introduced a policy of “Zero Tolerance” at its border with Mexico. Anyone attempting to enter the US without documentation would be prosecuted, even if it was a first offence. If they were travelling with children, their children would be taken from them. The policy was cancelled within weeks but not before thousands of families had been separated. Six years on, several hundred are still to be reunited. Migration is perhaps the most important battleground in this year’s presidential election. Both President Biden and his challenger, Donald Trump, have made recent visits to the border. And Zero Tolerance still resonates.Linda Pressly hears about the pain of separation as experienced by a man from Guatemala; speaks to the people still trying to put families back together; and asks if a new administration might turn again to Zero Tolerance in an attempt to deter would-be migrants to the United States.