In Pagans In The Promised Land he has distilled some of that information to offer proof of his theory that American government policy towards Native Americans has been justified by concepts of Christianity. He also categorizes the relationship of American governments towards Native Americans as one that follows an empire-domination model based on an inherent right of Christian rule by discovery.

While he offers various examples throughout the book substantiating his theory through the history of America, three concrete examples, or proofs, form the core of his argument. In 1493 Pope Alexander VI issued a Papal Bull known as Inter Caetera in response to a request from King Ferdinand and Queen Isabella of Spain to justify their claiming any lands that Christopher Columbus discovered or may discover in the future. The only codicil that the Pope added was that no Christian King could claim any land already claimed by another. The Pope saw this as being a way of spreading a Christian Empire, fulfilling his desire to subjugate non-Christian nations, by whatever means necessary, and making them all Christian.

Those landing at Plymouth Rock claimed the land in the name of the Puritan, Christian God, and after only a single generation had exercised dominion over the indigenous populations. They may not have exercised to the letter of Alexander's Papal Bull, as they weren't Catholic, but they sure followed its spirit through their treatment of the local indigenous population. Yet, according to Newcomb, while the Inter Caetera may have defined their relationship with Native Americans, it has been American governments likening themselves to the Israelites of the Old Testament in Exodus and America as "The Promised Land" that has had the farthest reaching consequences.

The Puritans saw themselves as the Chosen People and the New World as their promised land where they would be able to live as they wanted, but it didn't stop with them. Benjamin Franklin suggested to the Continental Congress that Moses leading the Israelites across the Red Sea should appear on the Great Seal of the United States, while Thomas Jefferson said it should depict the Israelites crossing into the Promised Land guided by clouds and fire. Both images were designed to reinforce the image of Americans as The Chosen People and America as the Promised Land.

Of course, as in the Old Testament, in America there were Canaanites who needed to be smitten before the Chosen People could move into their Promised Lands, and smitten they have been. According to various proofs offered by Newcomb throughout the book this mindset has permeated the attitude taken by America during their expansion across America and their treatment of Indigenous people's everywhere.