Remember that, if the people who are now backing Owen Smith had had their way, then Labour under David Miliband would have entered the Coalition in 2010, or at best offered no Opposition to it in any meaningful sense of the word.
They screamed off Ed Miliband's manifesto as the most left-wing in a generation. It was. But Theresa May has adopted at least the rhetoric and the aspirations of a very great deal of it.
She has become the Leader of one party when the Leader of the other was already Jeremy Corbyn. His presence now frames the entire political debate, at least in England, and pretty much in Wales as well.
UKIP has collapsed. The Right could not even get a candidate onto the ballot for Leader of the Conservative Party, with the result that there was no such ballot.
And the Right's candidate for Leader of the Labour Party, a man whose Wikipedia entry was all of seven nondescript lines long only two weeks ago, is having to pretend to support a programme the advancement of which by Andy Burnham last year would have stopped the Hard Left from even bothering to field a candidate.
But Corbyn is still going to beat him. Of course.
In 2020, and every 20 years thereafter, the Westminster and Holyrood elections will be on the same day. That will do the SNP no end of good, unfortunately.
The Lib Dems are experiencing something of a revival. That is one of the very few practical consequences of what is already almost the forgotten referendum on EU membership.
But the new order is of economically a very left-wing, and internationally an extremely pacific, Labour Party. Of which the Conservatives seek merely to be a more "moderate" version.
Yet even their own voters will often still not own up to supporting them, because they are "nasty". It was ever thus. The Heath Government was successfully depicted as viciously right-wing at the time. In many ways, it was.
Other than the SNP, such opposition as there is going to be, is going to be extraparliamentary as a matter of principle.
People do not join Trotskyist organisations as fully formed Trotskyists. They are trained into it by those organisations.
But no one starting out now would join the Socialist Party, previously Militant. They would join the Labour Party of Jeremy Corbyn. Possibly Momentum as well. But primarily, if not exclusively, the Labour Party.
In any case, the SP's members are entirely open about the fact that they would be in Labour if it would have them. If things had worked out as he had wished, then Dave Nellist would be a Labour MP to this day.
At a Corbyn rally last year, Tony Mulhearn read out the old Clause IV. Derek Hatton talks about the Liverpool City Council of his day in terms of "houses with gardens front and back".
All in all, not really Trots at all.
Leaving the SWP. Tiny but noisy, and undeniably well-organised, expect to see and hear a lot more of it.
Not, however, at the ballot box. It does not contest elections.
Oh, well, if you did want to vote against the new order, then there would always be the Lib Dems.