I've been thinking, and I think you should respect everyone. No matter the circumstances, who the person is or what they've done.
It doesn't need to be respect for his actions, circumstances or for what he/she has.
It should be respect for the fact that he/she is a human being.
Acknowledgement is important. When somebody says something they say it expecting an acknowledgement of the fact that their communication was understood.
When somebody does something they do it with an expectancy of somebody they care for or look up to to acknowledge the fact that they did that. Think the kid who cleans his room without anyone telling him, he wanted an acknowledgement, whether that acknowledgement is candy, dessert, or simply gratitude for the fact that he cleaned his room.
When a teen is being rebellious, he is doing it because previously he did not get an acknowledgement for who he is, and is expecting, knowingly or unknowingly, an acknowledgement for who he is.
So do try to acknowledge everyone for who they are. You don't have to agree, but you do need to acknowledge, for that is a human right. (In my humble opinion.)