The siege mentality also excuses the leader’s bad behavior. When our very existence is on the line we can’t be worrying about things like humility, sexual morality, honesty and basic decency. In times of war all is permissible. Even molesting teenagers can be overlooked because our group’s survival is at stake.

In the end, though, the siege mentality ends up being self-destructive. Groups smitten with the siege mentality filter out discordant facts and become more extreme versions of themselves, leading to further marginalization. They take mainstream loathing as a badge of honor and wind up taking pleasure in their most unattractive instincts.

The siege mentality ends up displacing whatever creed the group started with. Evangelical Christians, for example, had a humane model for leadership — servant leadership — but, feeling besieged, they swapped it for Donald Trump, for gladiator pagan leadership.

Why is this mind-set so prevalent now? Well, it’s partially because the country is divided and many groups feel under assault. According to a Pew Research Center poll, 64 percent of Americans believe that their group has been losing most of the time.

But that’s not the main reason the siege mentality is so prevalent. It’s because we’re in a historic transitional moment and the very foundations of society are now open to question.

In the 1960s the civil rights leaders suffered injustice and oppression. But they had a basic faith in the foundations of society. They wanted a place at the table.

Today people are more likely to think the table itself stinks, or there is no common table. Today Christians are more likely to argue that the liberal order itself is intolerant toward faith. Social justice warriors are prone to argue that America is racist and oppressive in its very bones. The evil is inherent in the basic structure.