The actor Robert De Niro has – after a brief period of abstention – returned to his robust public critique of Donald Trump, using his Palme d’Or acceptance speech at the Cannes film festival to newly attack the US president. Speaking during the opening ceremony of the 78th film festival in France, De Niro said that the US’s re-elected commander-in-chief posed a global threat. “In my country, we are fighting like hell for the democracy we once took for granted,” he said. “That affects all of us here, because art is the crucible that brings people together, like tonight. Art...