When the actor Kevin Spacey was filming the current series of House of Cards, with its brutally cynical take on American politics, he said he was worried that they may have gone too far. As the US presidential election reaches its vituperative climax, he now concedes they haven't gone far enough. The invective has reached new heights this week with Donald Trump claiming the election is being rigged and Hilary Clinton countering that he's unhinged and dangerous. Has political discourse ever been as poisonous? It's not as if we can look down from the moral high ground. When three High Court judges found that Parliament should have a say on Brexit their photos were splashed across the front pages with one newspaper headline branding them "enemies of the people". Ours is not, of course, the first age to fret about the quality of political discourse. Plato and Socrates did their fair share of lamenting, but the digital age has intensified the political cycle and ratcheted up the stakes. Is this all just part of the theatre of current affairs - an entertainment that we all are knowingly a part of and can tune in and out of at will? Or is a political discourse in which there is no longer any presumption of good faith between opponents not just morally bankrupt, but also dangerous? Is this a healthy revival of robust political engagement, or have we abandoned moderation as a moral virtue?