American politics in the era of President Donald Trump is a polarised, partisan arena. But still there are pillars of the US system of governance such as the constitution and the courts that are supposed to safeguard the liberty of all, irrespective of creed, colour or politics. HARDtalk’s Stephen Sackur speaks to David Cole, the legal director of the American Civil Liberties Union - the century-old guardian of citizen rights. Has the ACLU betrayed its mission by putting partisanship before principle in the age of Trump?Image: David Cole (Credit: Getty Images)