I bet you are a Thomas Sowell fan. Your post echoes one of his frequent themes. Dr. Sowell has written some great opinion pieces about liberals making themselves feel good at the expense of others, with minimal (if any) sacrifice on their own part. I too get so tired of liberals parading their supposed moral superiority...
While I have great respect for him and have read some of his writings, I don't follow him. What I wrote is simply my own opinion. Rush has also expressed similar idea over time. I don't think any of this is new.
Where I live (rural corn belt) we don't have that many liberals/leftists, so I don't have that many as acquaintances. Those I know, however, can be insufferably ignorant yet dogmatic on social/political issues (validating my point), yet friendly in a condescending way: The ego is alive and well in all of them. The most recent run in I had with an educator brought that out loud and clear. We no longer communicate after what I had to say to him in an email recently.