US President Donald Trump opened 16 days of celebrations for America’s 250th anniversary Wednesday with a rally-style speech – turning a national commemoration into a highly politicised showcase for his second-term agenda.The address, on Washington’s National Mall, underscored how Trump has reshaped the anniversary around his own brand of politics and showmanship, blurring the line between official celebration and campaign-style spectacle.The Republican leader eventually invoked the grand...