In 1948, this proclamation was composed, in the tradition and spirit of the U.S. Bill of Rights, as the free world's response to the atrocities committed by the Nazis. The Declaration is a direct product of the American conception of civil liberty.
Yet there are freedoms in this declaration which the United States has never actively promoted, let alone enshrined in law; which the United States has either tacitly or actively undermined in other nations; and which the United States has defended in the past but has recently, shamelessly, begun to violate.
If America wishes to be taken seriously as the "leader of the free world," it should behave as if the UDHR were the supreme law of the land, even to the extent of codifying the declaration into law.