Why do liberals use hyperbole and rhetoric rather than talk rationally about the issue?

I love having conversations and understand peoples views. Just learning the psyche of how people arrive at their beliefs. But every time I engage a liberal in conversation they will not support their beliefs with facts and logic. The will go to their credentials, tell me that their not stupid, call me names or someone else names. Despite my many efforts they do not say your wrong cause of this. Or I believe this because of XWZ. And they never ask why do we feel the way others do. I am not saying this to be mean. But when this has happened again and again, you have to conclude that something in liberals make them tick differently. Why do the feel the need to jump i others life's and take away their freedom i.e. Unions, cap and trade, dumb regulations(some are needed but the ones that are, are not implemented), spreading other peoples money etc. Why cant they be like, I don't agree with that but your free to do what you want this is America?