What aspect of American democracy is most closely related to the concept of natural law?

The aspect of the fundamental rights in American democracy is most closely related to the concept of natural law.

Explanation:

The rights that are dispensed to every single citizen of the United States by the United States Constitution enable the citizens to pursue a free life with the least restrictions. These rights guarantee that every individual gets to live his life to the natural best that he wishes to. Hence, the concept of natural law can be said to have embraced in the aspect of fundamental rights.