There is nothing that corrupts conservatives quite as much as the need to be nice.
Conservatives are natural optimists who see the world as being basically a nice place. They are nice because they think that the world is nice. That worldview is not reciprocated by the other side.
Where conservatives see a country store, liberals see an oppressive outpost of capitalism. Where conservatives see a family, liberals see abusive patriarchy, oppressive gender norms, religious indoctrination and apple pie. Our current broken family society is the outcome of a cultural war waged against families based on that viewpoint.
The left is convinced that the world is an evil place, that people are basically terrible and that they are the only thing standing between us and the return of human slavery.
It’s no wonder that liberals are so nasty.