US President Donald Trump wants to expel illegal immigrants and is threatening to withhold federal funding from "sanctuary cities”, cities that provide refuge to undocumented migrants. Millions of people are threatened with deportation. This puts the White House on a collision course with the state of California, where there is a large Hispanic community - and which is now seeking to become the country’s first "sanctuary state". Our correspondents report.
A programme prepared by Patrick Lovett, Charlotte Prudhomme and Florence Viala.