While I disagree with your opinion, it is immaterial to the discussion.
It is my assertion that the default American ethical standard is, and has always been the Judeo-Christian ethic. Our laws were built upon it, our sense of right and wrong is based upon it, Our sense of work and industry, fair play, charity, justice, mercy (even in battle), chastity, honor... All these come from the God of our fathers. Our social structures cannot survive without it.
It is so uniquely and pervasively American, that even if you were raised to worship otherwise, if you were raised in this country it is imbued in you. It is impossible to avoid.
To attempt to replace that ethic with something else, or to dissect it in order to remove the parts that are unpopular in the pop culture is to perilously and purposefully attack the root and foundation of our very being. It cannot be done.
America without God is not America at all, as our near history and present day attest.
Nice slogan. I don't disagee with the characterization of our culture being generally based on Judeo Christian ethics. My disagreement is over characterizing that as the basis for determining whether a particular piece of legislation is within the legitimate authority of the federal government.