Ever hear of a Zero Sum Game?
I'm sure you have. And you know it means for someone to win, someone has to lose. According to some, the wealthy win because the poor lose. It's a well known liberal/progressive economic concept- not an insult.
It's acutally refreshing to hear people starting to call a spade- a spade.
But to say that all liberals subscribe to the idea of zero sum is like saying all Muslims are terrorists.