I’ve always thought of liberals as seeing people in social levels, and who ever is the alpha male/female on that level will dominate the thought pattern of that group. Liberals will look down on people they think are beneath their level and worship those above them.
The only way to reach a liberal is to appear to be on a level above them.
My experience is that one on one it hinges on what you can subtly get liberals to reveal about them self to them self. I find that the best way to this is through leading questions whose answers you already know how to respond to. Always let the liberal think they are leading the conversation. Let them think they are the smart and informed one you are the one looking for answers. Once you have them in this position, with the appropriate questions you can lead them right where you want them to go, all the while they think they led conversation there.