Photo of drowned father and toddler daughter highlights US border crisis

The shocking image of the bodies of Oscar Martinez Ramirez and his tiny daughter Valeria, who drowned in the waters of the Rio Grande as they tried to get to the USA, is, Senator Elizabeth Warren told this programme, a tragic reminder of the “broken immigration system” in Donald Trump’s America.

The southern border is already a key election battleground, with growing outrage over conditions in detention centres, particularly for unaccompanied children.