What factors of character and circumstance justify Randy's assuming responsibility for and authority over Fort Repose? Is his thought in Chapter 7-- "When you had the responsibility you also had the right to command"--explanation enough?

Fort Repose is a disaster. There's no order, no teamwork, and no leadership. Randy is able to fill the leadership role, and he has the ability to bring the community together. Is he justified in his actions? Yes, he is. It is because of Randy and his friends that the fort is able to survive.

"When you had the responsibility you also had the right to command."

This quote is in its own way a double-edged sword. In this context and this situation it is most certainly appropriate. Note- it is not applicable to every circumstance.