Factors discussed:
- Belief systems, in which "fighting" is regarded as "wrong."
- Fear, feeling vulnerable to being hurt and bested; lacking the fire in the belly to go toe-to-toe.
- The dynamics of cultural polarization, in which each side becomes like a photographic negative of the other.
- The impact of the Vietnam War on a generation of dovish liberals and the Democratic Party.
See also my 2014 essay, “Right-wing Destructiveness Plus Liberal Weakness: The Dangerous Combination Behind America’s National Crisis.”
And this from 2022: “Why Liberal America Has Been Weak in Protecting the Nation.”