The Clinton–Trump race has been extraordinary. Two of the most unpopular presidential candidates ever have slugged it out through a bitter campaign. They are both – for different reasons – deeply polarising figures. Hillary Clinton is viewed with suspicion by Americans who have turned against what they regard as “the elite”. Donald Trump has exploited crudely divisive, sexist, even racist, rhetoric. The tone of the contest has been ugly. But there is historical precedent for much of this – divisive policy positions on slavery or the famous attack ads of the 1960s. How should we view this campaign compared to the candidates, rhetoric, policies and media climate of past elections? (Photo: Republican presidential candidate Donald Trump listens behind Democratic nominee Hillary Clinton as she answers a question i their presidential town hall debate at Washington University in St Louis, Missouri. Credit: Rick Wilking)