But doesn't the article @marckee posted show that the difference in beliefs between the voters who left, the voters who stayed, and the youth vote isn't that significant? Long term members tend to be a few points more moderate but there's no great ideological departure. The schism in the party isn't over beliefs, it's over willingness to compromise and how short term those compromises prove to be. Returning members initially left the party because they couldn't stomach the compromises, the mistakes and the warmongering. But these same members are the people that New Labour decided couldn't be kept as a visible, active element of a party that needed to win votes in Tory marginals.
I still think the fight in Labour is over pace of change and visual identity more than over significant ideological differences, but we've turned it into a really vicious civil war in which Jeremy Corbyn and Harriet Harman, two of our longest serving MPs are some how presented as opposites.