Corbyn's weakness is in his weak base in a PLP that mostly cannot wait for the election to be over to have the next pretext to get shot of him, either to reposition the party purely as a vote winning machine on behalf or monied corporate interests or else to get rid of a lame 'unpatriotic' leader who cannot win affection or respect.
As soon as May wins the election, a civil war and the possibility of a coup in Parliament is possible if Corbyn stands for re-election and cannot be removed because of continued membership support. Indeed, Mandelson and Blair are working with Progress and Lord Sainsbury to form a breakaway Progress Party.
The Deputy leader, Tom Watson, is a key figure in Progress and could be plotting with Blairites to stage an internal party coup. He lurks menacingly behind Corbyn like a thug at every opportunity to try and intimidate him and Corbyn only has rectitude enough to blank out these plotters 'as if' they were not there.
Even so, Corbyn's position is weak and his reaction to internal party dissent, especially from Watson, is to allow it to go on as if it was not there in preparation for the real business of politics that will go on once he can remove him. Corbyn has remained aloof from it, the better to position himself as martyr figure.
Corbyn needed to have stamped his moral authority on the PLP more than he has, using arguments and rhetoric with energy and zeal. All he can manage is flat, cautious statements as well as the Tony Benn style 'collegiate' approach in which divisions, in-fighting and plots is rationalised as 'diversity of opinion'.
The anti-Semitism controversy could have been resolved by clear moral leadership and him taking a position with precision and authority. But Corbyn doesn't believe in that as he naively thinks that getting round a table and talking things through with unsavoury figures is a substitute to setting clear lines of authority.
Hatred for Israeli policy has spilt over into anti-Semitism in certain part the Labour Party movement as they see Israel first as an outpost of US capitalism and imperialism and then 'the Jews' as all powerful in British politics and over Labour as a lobby group. Corbyn, wanting the Muslim vote, remained silent.
Part of the problem is that there is an Israeli lobby wanting to use money power and propaganda to steer the Labour Party towards Blairite norms. Their elegant, suave and ruthless representative in Britain is the emissary Mark Regev. His job to advocate Israel's battle against Hamas as one of the left against Islamofascism.
Corbyn could easily have drawn a distinction between criticism of Israeli state policy in respect of Gaza and the anti-Semitism as expressed by Hamas ideology. He failed to do that because he aligns with the underdog against 'the imperialist power' and retains silences on aspects of the struggle that don't fit the creed.
Bumbling on the Syria Question.
Corbyn does not understand the complexities of Middle East power politics. Ever since the Syrian Civil War broke out, the previous supposed unity of British Muslims 'against imperialism' has been shattered as many actually this time wanted military intervention against Assad for slaughtering Sunni co-religionists.
Corbyn had a problem framing this complicated issue where many British Sunnis were not against intervention in the way they were against Saddam Hussein in 2003. The best he could do was to call for a regional settlement involving all the Great Powers, the right one he stumbled on only through realising the West had already lost.
It was quite obvious that military intervention by the Western Powers to remove Assad would have the same result as it has elsewhere, as in Libya, by at least early 2013. Corbyn was only ever interested in the Syria Question according to what the West did or did not do: everything else was an afterthought.
Opposition to war has to be intelligent and constructive , based on objective knowledge and understanding of the geopolitical stakes for the regional and global powers concerned. Corbyn only ever seems interested in prating about the need for peace without actually understanding how and why wars start or escalate.
Corbyn is not so sharp as he never had to learn how to sharpen complicated issues into a rhetoric that would communicate the dangers of specific foreign policies. He used his backbench position to virtue signal in Parliament and please the crowd outside, the voices of protest and those otherwise ignored outside Westminster.
However, emitting pacific platitudes or anti-war riffs to a crowd does not translate necessarily into an understanding of complicated foreign policy dilemmas. In that sense, Corbyn's simplistic peace propaganda was just a mirror image of the simplistic approach Blair took towards war as an instrument of utopia.
Whereas Blair believed Labour's internationalism meant aligning with the US in wars to liberate people everywhere from the iron grip of dictatorship and terror, Corbyn simply believed the opposite: that dictators only existed as a total consequence of Western foreign policies in the first place and because of war.
Whereas Blair believed that determination to 'do it' in foreign policy was the way to reshape the world, Corbyn believed more in Britain setting a moral example of not doing, not selling weapons abroad, not having a war machine and that if the UK didn't do what it does, if it 'stopped', the world would be made better.
Both positions were shallow. But Blair's was obviously the far more destructive course and so, as the disasters of the Iraq War and even the war in Afghanistan became clear, Corbyn was bound to be seen as having been right all along and so the vacuity and emptiness of his stances seen as constancy of moral purpose and 'authority'.
Exercising authority does not mean regimenting people as Blair did. It would mean, at least, stating a case clearly with precision and sticking to it. Corbyn just doesn't have this ability, he seems always to be emerging later and reacting to events once they have been allowed to go on without him. That's not leadership.
The sluggish reaction to a potential international crisis over Trump's missile strikes in March 2017 made that plain. Corbyn needed to have come out immediately with a position on that. Instead he emerged a day later and reeled out a lame set of wooden platitudes about 'the need for a political settlement'.
This is why Corbyn cannot be imagined as a Prime Minister. He simply lacks quickness of thought and the necessary mental agility. 'Not being Blair' is not enough. A thoughtful leader rather than an impulsive one would be welcome, but not one who treats global power politics like a concerned Islington social worker.
Corbyn's failure is assured on June 8th 2017. His fans will rationalise his failure by pretending it was only due to media manipulation and his demonization and not due to his lack of political skills or the intuition, correct as it happens, that Corbyn is a shifty ideologue interested in the people and peace only as an abstraction.
Corbyn is undoubtedly sincere in hating injustice and hypocrisy. Yet that is always in danger of shading into moral nihilism or the idea that any opposition to Imperial Power means that any form of opposition is politically inevitable unless the root causes of the injustice are ripped up and the cause triumphs.
Corbyn no doubt abjures violence but, having lived a comfortable and sheltered life as middle class radical, he tends to believe naively that violence has causes that can be rationalised according to simplistic politically correct lines. In this sense he is as much a failure as Tony Blair who was quite similar in this sense.