I think your link is maybe a little off, or they killed the original page?
Seemed like it (once?) contained some interesting stuff.
gajin had trouble with the link.
I will check it out. Here is another shot at it:
The Motivations of Political Leftists.
http://tongue-tied2.blogspot.com/2006/06/what-appears-below-is-attempt-to.html
Here is a brilliant essay by Daniel Greenfield that comes to the same conclusion:
The Progressive Missionaries of Unhappiness
http://sultanknish.blogspot.com/2014/10/the-progressive-missionaries-of.html