Indeed - since when one is young and is happy to have high taxes (for others), high minimum wage (for oneself), subsidised housing / tuition for themselves.

When one gets older they are worried about one's children and later on worried about oneself. Frankly, they suddenly have things to loose - much easier to be happy to share when one is getting things from others after all.

IF there are people earning loads of money that donate a significant portion of their salary they are able to truly follow their beliefs. Others, like Union bosses whose only left wing facet is continuing to live in a subsidised council house don't really count; the Millibands have levels of luxury few of us will ever get and yet purport to be left wing.