What is the relationship between these documents, especially for interpreting the Constitution? There are several different possibilities.
1. Largely Unrelated. This is the conventional view in constitutional law. Under this view, one generally can ignore the Declaration when interpreting the Constitution. One justification is that the Declaration had a limited purpose – announcing to the world that the US was independent – and that was concluded by the end of the Revolutionary War.
2. Significant as a Document. Under this view, the principles announced in the Declaration are important guides to the meaning of the Constitution. The force of the Declaration comes from the fact that it is one of the foundational documents in US history. While not the standard view in either originalist or conventional constitutional law, it does have some adherents.
3. Significant as Evidence of Political Principles. Under this view, the Constitution should be interpreted in accordance with certain important political principles, such as natural law or traditional common law principles. The Declaration is evidence that natural law principles were widely accepted by the people in the latter part of the 18th The reason for employing these principles, however, is not that they are in the Declaration, but that they were widely accepted.