In a sense, the departures have already started. Quite a lot of people who were prominent in Labour politics during the election-winning years of Mr Blair have withdrawn from active politics, many in despair at the state of the party since 2010. Many of the backroom advisers and thinkers from that era who might have been expected to seek election to Parliament and the NEC have decided that they can have a nicer life outside politics, at least until their party sobers up. The result is that many of the MPs who arrived this year lean to the Left. The “Blairites” who remain active in Labour politics are looking like an increasingly marginalised and embattled minority.