DVD/Blu-ray: The Iron Lady (12) Meryl Streep gives a note-perfect portrait of an elderly lady bewildered with dementia. Unfortunately, that lady is Margaret Thatcher, who receives a compassionate biopic from Abi Morgan. Has any British prime minister been less deserving of one? The politics here are careless and crude; it skips over the bothersome riots, that Falklands business and the unemployment, favouring her warrior image, sweet marriage and current loneliness. "Mags: the musical"? "Pinochet: the Wonder Years"?