Is there a point of no return with entrenched elites?

I realise this is a question I’ve been trying to articulate for ages. This is how Paul Mason articulates it in the Guardian (my emphasis):

To the mature democracies of the world, the Panama Papers – as with the Lux Leaks, Swiss Leaks and numerous other data dumps before them – are a warning. If wealth equals power, then the doubling of ratio of wealth to income in the advanced economies since the 70s (see Piketty and Zucman 2014) could tilt power so far in the direction of a new hereditary elite that there is no return.

Is this possible? What would it mean? Is this a point of no return for a social formation? For a civilisation?