Mr Hughes claims that to point out that Thomas Jefferson was a slave holder is 'retrofitting of the past with one's own moral precepts'. This argument seems to come perilously close to the sort of moral relativism endorsed by some of the contemporary philosophical currents that Hughes is denouncing. Can we also apply no moral judgements to Lenin, Robespierre and Genghis Khan?
The argument is also misleading historically, in so far as it assumes that slavery was universally accepted in Jefferson's time. In fact, his contemporary, the high Tory Dr Johnson, regularly drank toasts 'to the next slave insurrection in the West Indies'; and the hypocrisy of those who pronounced on the rights of man while owning slaves was a common British criticism of the early United States.
Perhaps there might not be a 'politically correct' movement now if liberals in the past had done more to take their own proclaimed values seriously.