Dave rightly mocks Aaronovitch for saying that he could vote for Cameron. But of course, Aaro is only one of many ex-Tankies to have switched to managerialist ideology; there's also, among others, John Reid and Peter Mandelson.
There's no surprise here. Such a shift is entirely consistent with their youthful beliefs. Stalinism-Leninism and managerialism are really very similar.
Tankies only really supported the working class because they thought the laws of historical development favoured this class; Aaro's belief that "progessive" is a clear and obvious good thing suggests the legacy of historical determinism runs deep. And to old Tankies, morality consisted in being on the right side of history. As Lenin said:
We do not believe in an eternal morality, and we expose the falseness of all the fables about morality. Morality serves the purpose of helping human society rise to a higher level. (The tasks of the youth leagues, speech on October 2, 1920).
Today, it seems the forces of history helping human society to rise to a higher level consist not in the growing strength of the working class, but in the rise of globalization. Morality requires Tankies to support this.
It's entirely natural that, therefore, that they should switch their allegiance from the centralist hierarchies that claimed to support the interests of the working class to the centralist hierarchies that claim to want "modernization." Tankies always supported hierarchy.
As for freedom and equality, well - the Tankies never supported those.