The bulk of the Left of the Labour Party, having thoroughly swallowed the mendacious soft-focus "I'm really a Corbynite" leadership pitch of Kier Starmer, rapidly became disillusioned (and in some cases, defenestrated) when he started purging the Peoples Party in a singularly calculating manner.
And we know whose are the calculations: it's Mandelson, the preeminent British political strategist of the age.
I feel we may now summarise his 2019 thinking, and estimate his chances of success.
1. Corbyn has done a Thatcher**, potentially sterilising the Labour vote for years to come
2. The only chance of reversing that lies in someone who looks the part (besuited, established), grabs all the levers of power within the party AND ...
3. ... methodically, gratuitously, ruthlessly and flamboyantly takes every opportunity to do Corbyn and his acolytes down (in ways that Hague, IDS and Howard could never do to Thatcher). You don't want an excrescence of people who remind the electorate of Corbyn and, crucially, you don't need them; neither for their pitiful subscriptions NOR as election-time infantry - because elections are lost by sitting governments, and won by clever media strategies funded by big donations, not knocking on doors
And now we come to the reason why this all might come to fruition in less than a single political generation.
4. Johnson is always going to self-destruct: possibly sooner rather than later: the key is to be in position for when it happens
With any luck (thinks Peter) it'll be Johnson who, in turn, sterilises the Tory Party as did Thatcher, for another decade of Mandelsonian influence.
Looks like it's going to work. Still: at least Mandelson is intensely relaxed about people getting filthy rich, eh?
** there's many a Thatcherite that has been in 30-year denial on this. They have forgotten, or may never have tried, getting support for the Party during the leaderships of the aforesaid Hague, IDS and Howard. Some things are never forgotten or forgiven by the electorate: Corbyn committed that kind of sin, and so IMHO has Johnson.