It's only when people become tribal that the positions no longer matter. They devolve into the thinking that no matter what their tribe does is the right thing to do. And anything the other tribe does is the wrong thing. That is the problem in today's politics. I would further argue that it is the tribalism that leads to political murder that you speak of.
I consider myself to be in no tribes and make my decisions on what I think is best for me and my family. And from that standpoint, I'd wouldn't mind hearing what specific liberal policies that you think are resulting in overt violence and murder. Because in my opinion, irrational people combined with tribalism is what leads to the violence you're referring to. I mean, irrational people commit violence without even belonging to a tribe. Adding the tribalism just gives them more "enemies".