Define "fails."
My point is that calling a particular policy "Keynesian" does not mean it is necessarily destined for failure.
And it is often possible to argue that even with a "failed" policy things might have been even worse without it.
History (and intellect) has ALWAYS shown Keynes as a failed economist and the politicians that follow his failed philosophy.
If you want to try and argue that the bastardized Keynesian practices of the past 10 years prevented things from getting worse then they are then you are mistaken.
When governments attempt to prevent markets from correcting themselves through policy intervention they are just kicking the can down the road. They did it in 2001 and again and again til the point where we find ourselves now.