Blair and the Iraq war shoulder a huge responsibility for why Labour is so divided at the moment.
On one-side you have people who were anti-war from the beginning and despise any Blairite MP in the party (there are a lot left). Another problem with these MPs is that they're basically 'Tory-lite'. The voting record of some is indistinguishable from the most hardened Tory.
Any then you have the Labour voters who call themselves 'moderates' or 'centrists', who don't really mind all of that and despise the likes of Corbyn and anyone a bit on the left. These are the type of people who think we should have another referendum on Brexit, who won't learn the lessons of the previous failings of the Labour party in becoming out of touch with the 'ordinary man' etc.
You also can't overstate the impact of Brexit on this election. Many people seem willing to overlook the threat to the NHS, pensions, the Tories poor record RE foodbanks and homelessness etc., just to get Brexit pushed through in as 'hard' a way as possible. Madness if you ask me, but this is the way things are going. Things aren't going to get better until we hit rock bottom, but unfortunately people seem so blind at the moment that we have a long way to go. Perhaps then we'll start to see the rise of Labour again.
Oh and the media absolutely can not be discounted as having huge influence. You only need to look to recent history and the propaganda of the Nazi party to see how devastatingly effective media campaigns can be. And just as it was then in Germany, they remain hugely poweful in the UK today. And make no mistake where the loyalties of the UK Press lie:
Daily Mail - owned by DMG media with Viscount Rothemere at the helm. As if the title gave you any doubt, Tory through and through. A non-dom who pays no tax on his stately home. Backed Tory/Lib Dem in last election. The Metro also comes under this media group.
Daily Telegraph - owned by the Barclay Brothers (Sir Frederick and Sir David..) Reclusive billionaires, friends of Thatcher and documented tax avoiders. Backed Tories in last election.
The Sun/The Times - Rupert Murdoch. I don't intend to waste much time writing about him. See: Hillsbrough, phone hacking, headlines consisting of vile lies (which result in hidden retractions/apologies) that are too numerous to count. You also need look no further than Fox News to see the damage that Murdoch and his empire can do to credible news reporting. Also Thatcher's mate.
Daily Express/Star. Backed UKIP in the last election. Owned by Richard Desmond. Donated over a million pounds to UKIP.
The Guardian and The Mirror and the papers generally backing Labour, although the Guardian can't stop itself from attacking Corbyn (the liberal commentators such as those featured in the Guardian will be the end of us). Guardian is owned by Scott Trust LTD, the Mirror by Trinity Mirror.