Rather than the Illuminati, the Civil War, or the Zionist movement, I'm betting this is influenced by yet another repository of Old Testament inspired imagery, Rastafarianism-via-reggae. The Rastafari religion conceptualizes itself as the fourth Abrahamic religion. The four, in historical order, are Judaism, via Abraham's grandson Jacob/Israel, Christianity, via Israel's descendant David, Islam, via Abraham's son Ishmael (Jacob's half-uncle), and finally Rastafarianism, which reveres Emperor Haile Selassie I, who is said to have been a direct descendant of David, via his son Solomon's liaison with the (Ethiopian) Queen of Sheba. Two major concepts in the religion are "Zion," representing the forces of good, and "Babylon," representing the forces of evil.
Rastafarian imagery is found in a lot of popular reggae music, including that of the prominent Rastafarian, and most famous international exponent of the style, Bob Marley. Marley's music, as well as those of many of his contemporaries, also frequently referenced the American cowboy and gangster movies popular in the Caribbean islands at the time.
Since this song has a light, but clear reggae influence, I'm guessing that the lyric is a tip of the hat, if not a particularly coherent one, to both the cowboy ("sharpshooter") and Rastafarian ("Zion") references in classic reggae, one written more with attention to the sound and the feel of the words then their actual meaning.