Does a mob have moral authority?
No more than an individual.
All things being equal, a group of people does not have the right to do anything that an individual can’t do.
Let me explain by example.
Say one of your neighbors – let’s call her Jill – falls seriously ill and can’t pay her medical bills. You clearly don’t have the right to break into your neighbor Jack’s house, tie him up, steal all of his cash and give it to Jill. Even the fact that you acted out of pure motives doesn’t justify the robbery.
But let’s say you get together with nearly everybody in the neighborhood to discuss Jill’s plight. You all agree that you must help her. So, the whole group goes to Jack’s house, ties him up, steals all of his money and gives it to Jill.
Does the fact that the majority of your neighbors participate in its planning and execution justify the robbery?
Of course not.
Two people can’t morally or ethically engage in an act that an individual cannot morally or ethically commit. Neither can three. Nor 10. Adding more people to the group doesn’t change moral/ethical equation. Even 100,000 people don’t have the right to act in a way that is morally/ethically prohibited to the individual.
Obviously, this has significant ramifications on how we organize society and the legitimacy of the state
But some will object that voting gives the group some kind elevated moral authority.
A simple thought experiment proves this untrue. Say you and a group of nine others vote 9-1 to kill Jack, steal his cash and give it to Jill. Obviously the fact that the majority approved the action doesn’t justify it.
What if Jack gets to participate in the vote? Does that morally/ethically sanction his murder?
I suppose it could, but only if Jack was stupid enough to specifically consent to being bound by a vote to kill him. Obviously, not a highly likely scenario. And the fact that Jack agreed at some point to abide by a vote on, say, how to divide up food would not justify the group later voting to kill him for Jill’s benefit. His consent to one action doesn’t create blanket consent for the majority to act in any way it chooses.
Taking it a step further, the mere fact that you belong to a group doesn’t automatically subject you to majority rule.
Imagine Jack went out with a bunch of friends, and while he was in the bathroom, the rest of the group orders a pizza. When Jack gets back, they demand he pitch in $5. When Jack protests, they tell him, “Look, we took a vote and decided to buy pizza; now pay up.” Of course, Jack doesn’t have any moral/ethical obligation to contribute to a pizza he didn’t want nor did he order. Even if Jack returned from the bathroom in time for the vote, it still wouldn’t bind him unless he agreed that pitching in for food was part of the deal when he joined the group in the first place.
For voting to maintain any real moral/ethical standing, each person must specifically consent to submit to the authority of the group on each activity subject to a vote.
But government rarely works that way.