How do you measure success in politics? Is it by the elections that you win and the jobs that you hold? Or is it by the change you bring about in the world?

By the first measure, Nigel Farage is largely a failure. Yes, he holds a seat in the European Parliament, as do several other members of his party. But Ukip has utterly failed to break into the Commons at Westminster. Its only MP, Douglas Carswell, is really there as a result of a personal mandate, and is largely estranged from Mr Farage anyway.