Substantive due process is a constitutional doctrine that protects certain fundamental rights from government interference, even if the procedures used to enforce those rights appear to follow legal protocols. It goes beyond mere procedural requirements and is concerned with the essence and substance of rights. In essence, substantive due process aims to ensure that laws and governmental actions do not infringe upon individual liberties that are deemed fundamental, such as the right to privacy, the right to marry, and the right to raise one's children.
Your analysis mentions that substantive due process "centers on the idea of fairness limiting the power of the government," which is a crucial aspect. This principle serves as a check on government authority, ensuring that laws are not only followed but also just and reasonable in their application to individual rights.
In summary, substantive due process focuses on the fundamental fairness and protection of individual rights beyond just procedural safeguards in the legal system. It emphasizes the importance of the substance of the law itself in maintaining justice and safeguarding personal freedoms.