Bi-partisan political activity

my parents are both registered republicans. my older brother is registered independant and my younger brother and I are registered democrat. All we need is my sister to register liberal or green party and the gangs all here. Yet, we can still live and communicate under one roof without problems. But I noticed that when I had conversations with a few people that their opinion of me or someones opinion of them changed based solely on their registered party. I found this to be troubling because their political party only determines their views on the ways in which certain things should be run or directed or dealt. This is not even the case 100% of the time. The person has not changed otherwise. I found these things to be shocking because I found myself arguing with friends and even some family members about the future of this country, be it good or bad. I am upset to find that silly things like politics can have such an impact on friends and family. Hence the power of a label:(