Glad you asked:
The principle feature of American liberalism is sanctimoniousness. By loudly denouncing all bad things - war and hunger and
date rape - liberals testify to their own terrific goodness. More important, they promote themselves to membership in a
self-selecting elite of those who care deeply about such things. It's a kind of natural aristocracy, and the wonderful thing
about this aristocracy is that you don't have to be brave, smart, strong or even lucky to join it, you just have to be liberal.
P.J. ORourke
That sums it up fairly well,
There are of course a long list of CAUSES for which the “liberal” bleeds but the reason for their doing so was covered concisely and completely.
Thank you.