Are we now a Christian nation?

Not really. Have you ever seen the Supreme Court Building? The words “Thou shalt have no other gods than me” aren’t there. Moses, as one of many historical lawgivers, is shown in several places, along with such historical lawgivers as Solon, Confucius, and Muhammad. This page from the Supreme Court’s website has links to a number of PDF files describing different aspects of the building’s architecture; note especially the north and south friezes (PDF file) in the Supreme Court chamber, where the Biblical figures Moses and Solomon share equal billing with Menes (legendary first king of Egypt), Hammurabi, Lycurgus (formulator of the Spartan law code), Solon, Draco (hey, his laws were proverbially “Draconian”, but they were laws), Confucius, Octavian (the Emperor Augustus), Justinian, Muhammad (a shout out to sharia as one of the world’s notable law codes from the Supreme Court), Charlemagne, King John (for letting the Magna Carta be extorted from him), Louis IX, Hugo Grotius, Blackstone, John Marshall, and Napoleon (for the Code Napoleon, of course, not for trying to invade Russia in the winter). Moses also appears on the east pediment (PDF file), along with Confucius and Solon again. (The tablets Moses are holding here are blank. The tablets on the frieze in the interior of the building do have some Hebrew characters which I am told do spell out part of the Ten Commandments, although I have heard that the part which is visible doesn’t include any of the “No other gods before me” part; i.e., none of what Protestants normally consider to be the first four commandments dealing with man’s relationship with God.) The “significant events in the evolution of justice in the Western tradition” illustrated on the building’s bronze doors (PDF file) don’t include any Biblical stories. In other words, a celebration of law, not religious faith, and most certainly including “appropriate or necessary recognition of other religions’ commandments”.