Mosiah abdicated the throne to establish a new political order among the Nephites. This chapter teaches us a great deal about liberty and the burdens it places upon those who would live free. Our ability to live as free men and women depends upon our righteousness. Even good laws are only sustainable if people choose to live according to them. There is a tipping point in a free society. When enough people choose evil, there is no amount of enforcement that can protect society from the consequences of it. Mosiah put it this way:
26 Now it is not common that the voice of the people desireth anything contrary to that which is right; but it is common for the lesser part of the people to desire that which is not right; therefore this shall ye observe and make it your law—to do your business by the voice of the people.
27 And if the time comes that the voice of the people doth choose iniquity, then is the time that the judgments of God will come upon you; yea, then is the time he will visit you with great destruction even as he has hitherto visited this land.
In a free society, men and women are not at liberty to do whatever they want. Liberty only works if people accept responsibility for their actions and conform themselves to the social contract and obey the laws. Mosiah's people had the vision as they understood his teachings.
38 Therefore they relinquished their desires for a king, and became exceedingly anxious that every man should have an equal chance throughout all the land; yea, and every man expressed a willingness to answer for his own sins.
It's that willingness to answer for our own sins that makes a free society possible.