Less than a year ago, Jeremy Corbyn was Labour’s candidate to be prime minister.
Now, he has been cast into the wilderness, suspended from the party, by his successor as Labour leader, Sir Keir Starmer.
The ruthless action by Sir Keir looks like the most brutal purge of the Labour left since Neil Kinnock took on the Militant Tendency in the 1980s.
Was Sir Keir hoping for Mr Corbyn’s unapologetic reaction, so that he could suspend his predecessor? He would no doubt dismiss that as a conspiracy theory too far.
Mr Corbyn’s crime, however, in the eyes of the former director of public prosecutions who now leads the party, was not his record on antisemitism during his tenure as Labour leader.
Instead, it was his defiant reaction to the Equalities and Human Rights Commission report, claiming the issue had been “dramatically overstated for political reasons”.
It was his lack of remorse, his failure to apologise, his denial that he was “part of the problem” and claim that the antisemitism furore had been exaggerated.
Mr Corbyn’s suspension comes four years after his oldest and closest friend in politics, Ken Livingstone, was suspended from the party in April 2106.
To this day, Mr Livingstone – a former member of the party’s national executive and, after an initial period as an independent, Labour mayor of London – remains out in the cold.
If Mr Corbyn is out of the party for as long as four years, he won’t be able to stand as Labour candidate in Islington North – or anywhere else – at the next election.
If that’s the case it will be an ignominious end to a Parliamentary career spanning almost 40 years, pursuing left-wing causes such as unilateral nuclear disarmament with vigour.
But as he demonstrated with the provocative reaction to the EHRC report that got him suspended, Mr Corbyn has served notice that he won’t go without a fight.
And even if he is forced out of Parliament, Mr Corbyn’s hard-left crusade will go on, as his hero Tony Benn’s did when he stepped down as an MP.
Before then, however, Sir Keir must prepare himself for a potentially bloody civil war with the Left.