Past
There were four different groups of social classes in pre-contact Hawaii. There were the ali'i, kahuna, makaainana, and kauwa. The ali'i were the cheifs of different sections of the islands. They were thought to be descendants of the gods. The kahunas were the priests and skilled craftsmen. They were also the close advisers of the ali'i. The makaainana were the common people, and the kauwa were the outcasts. There were many prohibitions on the makaainana when it came to the ali'i. The ali'i had the power to save the life of a person or kill a person with the uttering of a single phrase. So ultimately, the ali'i held the laws in the palm of his hand due to the kapu system. There were also laws that restricted what the different genders could and could not do, but those will be better explained in the section on gender roles.
Present
When the westerners came to Hawaii they brought their social and political views along with them. They realized that they did not like the absolute monarchy and kapu system so they overthrew it. In 1819, King Kamahemahe II declared an end to the kapu system and showed he was serious about his decision by eating and drinking with women which was against the kapu system. From there the westerners found an opportunity to influence their ideas into the Hawaiian law system and Hawaii formed into a constitutional monarchy.
Future
Now that Hawaii is part of the United Stated, we run on the same law system as the rest of America. In the future there will probably not be to much change to this and it will probably remain the way it is right now. There is a very "manini" chance that Hawaii will become a sovereign nation again and become a monarchy again, let alone bring back the kapu system.