The post-war consensus of nationalising key industries, taxing the rich at progressive rates and maintaining large unions was ended in the 80s, and has since fundamentally changed politics. Nowadays, centre-left parties stand on platforms in favour (however begrudgingly) of privatisations and tax cuts.
What can be done to prevent this, turning the tide so that in the UK at least, social democracy is more prevalent. By this, I mean more non-militant Labour governments.