"Moral legitimacy" refers to the belief that an action or behavior is morally acceptable and ethically justified. It means that the action is seen as right and proper according to widely shared moral principles and values. Full definition
The imperial state needs religion to provide moral legitimacy for its rule. (firstthings.com)
Unmoved by the prospect of the end of democracy, and skeptical about the existence of a moral law, they might say that the system still «works» to the satisfaction of the great majority and, niceties about moral legitimacy aside, we will muddle through so long as that continues to be the case. (firstthings.com)
The third issue conservationists do not typically address is the questionable moral legitimacy of lethal management. (theconversation.com)