Most of it was psychological, not unlike lines painted on a road acting like a divider. The only barrier, most places, is a mental one. Even when a road is empty, most people obey out of a sense of safety and respect for 3 ton bullets.

Windows on houses, also a psychological barrier to entry. They’re glass, anyone can break them with little effort. Take away the mental restraint and you have every zombie movie ever made.

Belief in the constitution, the democratic republic of America, and the rule of law does not exist with MAGA. As such, there are no mental guardrails to hold anything dictatorial or destructive back.