What Identifies America as a Christian Nation?

Rousas John Rushdoony (April 25, 1916 – February 8, 2001) was a Calvinist philosopher, historian, and theologian and is widely credited as the father of Christian Reconstructionism and an inspiration for the modern Christian homeschool movement. His followers and critics have argued that his thought exerts considerable influence on the Christian right. 

Here is a link to an audio by RJ Rushdoony on America as a Christian Nation that I think is worth listening to and discussing.
http://chalcedon.edu/research/audio/what-identifies-america-as-a-christian-nation/

 If America used the Bible as the standard for laws nationally and within states, would this be good or bad for unbelievers? How did the Puritans handle this issue? Here are a few verses to consider summarizing toward that end. 

Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit,  Matt 28:19

And thou shalt not glean thy vineyard, neither shalt thou gather every grape of thy vineyard; thou shalt leave them for the poor and stranger: I am the LORD your God. Lev 19:10

And if a stranger sojourn with thee in your land, ye shall not vex him. Lev 19:33

But the stranger that dwelleth with you shall be unto you as one born among you, and thou shalt love him as thyself; for ye were strangers in the land of Egypt: I am the LORD your God. Lev 19:34

Ye shall have one manner of law, as well for the stranger, as for one of your own country: for I am the LORD your God. Lev 24:22