Trying to make head or tail of political schisms

 I have not been a very political animal until this year. I felt - in common, I suspect, with many of the populace - that "all politicians are the same".  I live in a safe Conservative constituency, where an earthquake of Richter-scale 7 proportions would be necessary to unseat our current MP. He's a nice chap, but without exception he votes the Party line in debates. So although I have always dutifully gone to vote I never had much hope that it would change anything.

2015 UK Labour Leadership election

Ed Miliband resigned as leader due to poor Labour results in the 2015 General Election, and a leadership contest ensued.
Following the Collins review, the party's internal electoral system had been revised to a pure "one member, one vote" system:  previously one-third weight was given to the votes of Parliamentary Labour Party members, one-third to individual Labour Party members, and one third to the Unions and Affiliates. (1)
Now, members and registered and affiliated supporters all receive a maximum of one vote and all votes are weighted equally. This gives the grass-roots membership far more influence.
Jeremy Corbyn stood for the leadership at the last minute with the support of 36 MPs. A number of prominent Labour figures, including Gordon Brown, Tony Blair, Jack Straw, David Miliband and Alastair Campbell, claimed that Corbyn as leader would leave the party unelectable in another General Election. However, Corbyn was decisively elected by Labour Party members in the first round, with 59.5% of the votes.

Policies

What is it about Corbyn's policies which have triggered such a huge response in voters?
Return of the NHS to complete public ownership?
Free education from primary to tertiary level?
Re-nationalisation of the railways and nationalisation of some heavy industries (eg steelmaking)?
I think it is primarily his principle that political decisions need to serve the best interests of "the man or woman in the street" rather than those of large businesses and economic interests.

Party response

This is where it gets dirty. We as a nation have got so used to right-wing policies over the last 30 years (even with "New Labour" in Government) that this shift towards traditional Labour values has been dubbed "Trotskyist". Although I don't think Corbyn's policies are those of communism, but of democratic socialism, clearly the elected Labour MPs don't feel he's got what it takes to win a General Election. A leadership challenge was first discussed in the British press in November 2015 when the PLP was split over Britain's participation in air strikes in Syria.  Another challenge was predicted in April 2016 after Ken Livingstone's allegedly anti-semitic comments led to his suspension; Shadow Cabinet members allegedly held talks with plotters.

The EU Referendum on 23 June

Corbyn spoke to Labour rallies throughout Britain advising that we should remain in Europe. He had previously been critical of the EU, and this didn't change, but he advised remaining in the Union to reform it from within. However, the position he took, and his reasoning, were not susceptible of use in media soundbites - and such a position was easily construed as weakness by both Remainers and Leavers. It was very little reported compared to louder, brasher mouths uttering promises that, immediately after the Leave vote, were admitted to be lies.
Journalists at The Guardian reported that a small group of Labour MPs and advisers had been talking about a 'movement' against Corbyn to take place on 24 June  ie, immediately the Referendum was decided.
On 25 June, a 'Saving Labour' campaign website was created, to encourage members of the public to email MPs to urge them not to back Corbyn. Hilary Benn, Shadow Foreign Secretary, contacted members of the Shadow Cabinet to inform them that he had lost confidence in Corbyn. Corbyn sacked him. At least 20 MPs resigned or were dismissed from the Shadow Cabinet over the next few days. A vote of no confidence in Corbyn was made by the Parliamentary Labour Party (PLP) on 28 June, with Corbyn losing the vote by 172 to 40. He however insisted that his mandate came from the party membership, and he refused to stand down. On 8 July he challenged the rebels to put up  candidates against him.
Over 100,000 new members were reported to have joined the Labour Party by that date, taking membership numbers above 500,000.
The party's National Executive Committee (NEC) met on 12 July 2016 to set a timetable and procedure for the election. They decided by secret ballot that the incumbent leader would automatically be on the ballot in any leadership election. They also decided, contrary to usage over the previous 7 years, not to allow the members who had joined the party in the past six months to vote in the leadership election. Approximately 130,000 new members who had joined since the EU referendum would be unable to vote - unless they registered as "Registered supporters" at a fee of £25. This angered me more than the resuscitation of the six-month rule; it looked like a cynical attempt to prevent the poorest of these new members voting, on the assumption that they were the ones likely to support Corbyn.
Angela Eagle (MP for Wallasey since 1992) and Owen Smith (MP for Pontypridd since 2010) stood against Corbyn. Nine other Labour MPs declined to stand. Eagle withdrew from the campaign after a short time leaving a 2-horse race between Corbyn and Smith.
Labour donor Michael Foster brought a High Court legal challenge to contest the NEC's interpretation of the rules that allowed Corbyn to be a candidate without having to secure nominations from Labour MPs/MEPs. On 26 July 2016 the High Court ruled that there was no basis to challenge the NEC's decision.
The Collins Review of leadership elections had concluded that the eligible electorate would include members without qualification; so Christine Evangelou and others brought an English contract law case against its General Secretary, Iain McNicol on behalf of the whole party, concerning the eligibility of members to vote if they joined the party after 12 January 2016 (i.e. less than six months before the start of voting). An initial ruling that these members could vote was overturned by the Court of Appeal a few days later. The "£25 for a vote" arrangement however still stood...
The latest is that the Labour Party appears to be stripping people of the right to vote - in a somewhat selective manner. "The compliance unit is working through applications to check whether the 180,000 new registered supporters who signed up to take part in the vote are eligible, or if some are members of, or public advocates for, other groups."..."[John] McDonnell claimed the party was exercising double standards in suspending [Ronnie] Draper while allowing long-time party donor Lord Sainsbury to remain a member, despite having given more than £2m to the Liberal Democrats." (2)
What the actual F does this political party think it is doing to itself?

The Other Lot

While all this internal strife was going on in the Labour Party, the Conservatives also fell apart. After the EU Referendum David Cameron resigned because the vote went for Leave rather than Remain. Smartest move he ever made. We had a brief nightmare vision of Boris Johnson (3) as a possible Prime Minister - and woke to the reality of Theresa May. And, despite her support for the Leave vote, she's showing a canny reluctance to invoke Article 50 (4) which would trigger the UK's actual exit from the European Union. But by contrast with Labour, the Conservative party has had no challenge to its basic policies, and so it has rapidly glued itself back together.