2 For as their laws and their governments were established by the voice of the people, and they who chose evil were more numerous than they who chose good, therefore they were ripening for destruction, for the laws had become corrupted.
4 And it came to pass that Nephi had become weary because of their iniquity; and he yielded up the judgment-seat, and took it upon him to preach the word of God all the remainder of his days, and his brother Lehi also, all the remainder of his days;
The transformation of the people of Nephi from a righteous people to one where a majority desired iniquity happened with dramatic speed. This is a frightening cautionary tale for our day. Values and mores which have long held sway can quickly give way. In the past decade in the United States we have seen such a rapid change in social and moral views. In some regards there have been some positive changes. But on the other hand, what was once seen as right is now seen as wrong and what is wrong is declared as right.
Mormon notes that Nephi resigned the judgment-seat. But I wonder, did he have a choice? If the voice of the people established the government and the laws, then could Nephi really retain his seat for long? Or would those who corrupted the laws also seek a new chief judge? I suspect that something more dramatic than a voluntary resignation may have been happening here. As the people grew more wicked, it is likely that they could not tolerate a leader such as Nephi who preached righteousness.