The biblical Israel is not just an example of a Godly nation. It is not one among many, such America or any other self-identified Christian nation might be lined up alongside it. Israel was unique. It was the particular agent through which God acted to free everyone and everything, which came to a climax in the body of Christ two thousand years ago.
Thus, the actions of ancient Israel to purge Pagans within its ranks cannot serve as a template for political policy beyond Israel today. It cannot guide followers of Jesus in the wider world. Not ever. America is not the new Israel. God’s relationship with Israel can only guide us in the church, in the body of Christ, which is the ethne, the nations engrafted into Israel. God’s cleansing of Israel is only relevant for issues idolatry within the church. And even there, we live in the shadow of the cross so scripture needs to be read Christologically, with the character of Christ as its focus. If the Old Testament offers any guidance for us in the public domain, Christians should look, not to the prophets within Palastine, but the prophets who ventured beyond it. Prophets like Jonah and Daniel. Prophets who, incidentally, learned to bless nations beyond Israel, to bless people beyond the people of God.