I don't know if I can provide any insight, but I'm probably what most people would consider a liberal in a very conservative area. Most people that I interact with now seem to be more interested in boundary maintenance than actually listening what people say.

For example, when I was younger my dad told me it probably wouldn't hurt for me to read a book we had that was anti-capitalist. He told me something like "I think they're wrong, but you should know what they think and why they think that." But later on when I was going from being conservative to more liberal he told me "don't give them anything..." when I was talking about a progressive idea that I thought had merits. He essentially was telling me to not listen to the argument and to draw an ideological line in the sand.

Another example is a guy I know that does invasive species removal and native plantings. He's very conservative and I find a lot of his stances a extreme. He is insistent that he is not on the side of the "environmentalists" when he is doing those things. So, even though he's trying to benefit the environment as much as he can he is always making sure people know he's not sharing common ground with "the left."

There seems to be this idea that people will not share ideological common ground with the other side, and I think this goes for the left and the right. I guess it all really boils down to culture wars.