Radical religion existed well before radical anti-religion.
For example, the monarchy had used a radicalized form of Christianity (the Divine Right of Kings) to claim that kings drew their authority from an ancient covenant with God. The monarchs of old presented a conflict driven view of history in which the monarchs were the righteous rulers in eternal conflict against tyrants and other rogues.
The Islamic jihad is a radicalized approach to religion that has been around for millennia.
By the time of the US Revolution, radicalized religion had lost much of its appeal. The groups that had used radical religion sought other paths to power.
The Hanoverian Kings of England were German. The Hanoverian Kings funded the Germany Universities and sponsored work to reframe the message of the monarchy as progressive. This effort spawned most of the "isms" of the modern age including progressivism, liberalism and (yes) conservatism.
The best example of this new thought was Hegel's Philosophy of History. Hegel was a royalist (a conservative). He presented a conflict driven version of history which staged the Germanic people as the up and coming nation on the world stage. Hegel was created pseudo-philosophical race-based religion. The Nazis were direct descendants of this chain of thought.
A central feature of Hegel's philosophy is a redefinition of freedom in which freedom is slavery and slavery freedom. This ideal continues today with people who seek freedom by creating ever greater dependency on the state.
Hegel was part of a royalist reactionary movement. His ideal was the restoration of central monarchy. The next generation (the Young Hegelians) produced a radical left wing philosophy.
Famous Young Hegelians include Feuerbach. Feuerbach realized that radical anti-religion could be as affective in consolidating power as radical religion. This was especially true in an age when people were tired of religious war.
Marx perfected the radicalization process and created a radical philosophy that was far more virulent then Hegelianism.
It is important to remember that Modern Radicalism took place on both the right and left. Many people hold up Naziism and Fascism as right-wing radicalism and Communism as left-wing radicalism.
The radical philosophies that led to genocide in the twentieth century were produced by the reactionary and radicalization process of the nineteenth century.
These reactionary movements trace back to the ideas of the Divine Right of Kings and the tradition of supporting secular authorities with fantastical conflict driven versions of history to support claims to secular authority.
For this reason, I am not happy to see Glenn Beck pursuing the ideas of Covenant America. The idea that one group has a direct Covenant with God which justifies its hegemony over others is the heart of the radicalization process.
The American Covenant theory holds that the American Revolution was run by God as part of a master plan. In this master plan, both the Declaration of Independence and the Constitution of the United States were revealed by God to establish the conditions necessary for the restoration of God's true church in the Latter Days.
The restoration of the church, of course, happened with the revelation of the Book of Mormon which taught man the true history of the planet. The specifics of the new covenant came with revelation of the Doctrine and the Covenants.
The D&C has many exciting revelations such as the restoration of polygamy for members of the patriarchy and the revelation that the Heavenly Father is not one God but one god in a political hierarchy of gods.
I agree that it is compelling to think that the Constitution was revealed by God as part of a greater revelation. It is compelling to believe that the words of the original constitution are scriptural and are equivalent to the Bible, The BoM and D&C. (NOTE: Amendments with numbers greater than ten are apocrypha).
The theory that the Consitution is of divine origins is truly compelling, but if the theory is not correct, then American Convenant Theory is a theory that might undermine and not strenghten the Constitution.
The idea that the words in the Constitution were revealed by God and are on par with other revelations of the Seer, Relevator and Prophet add religious authority to the Constitution, but what if the Seer, Relevator and Prophet is just a politically ambitious partisan, then our attempts to build a religion around the American Covenant has reduced the American Experiment in self rule to the long line of other false prophecies.
In practice, these theories in which one group of righteous people claim a special covenant with God have led to division. The righteous are thrown into conflict with those outside the covenant (the evil gentiles). Deep structural divisions tend to end poorly.
In WWII, the Nazis held that the Aryan Race was chosen by the world spirit as the master race that would rise to hegemony. In order for this stage in the evolution of man to reach fruition, they had to kill everybody from the previous stage of development.
Now, it is true that, throughout history, scholars have come up with all sorts of reasons to claim that their group is the chosen group and is empowered by providence to oppress the villainous others. This type of divisive thinking is at the root of much of the radicalization of the last two centuries.
I am really sad to see Glenn Beck pushing a type of thinking that led previous generations astray. By pushing the idea that there are righteous Americans who are part of the covenant with God and evil gentiles who need to be repressed, Glenn Beck is just making the world worse.
This type of divisive thinking undermines society as whole.
For example, I happen to agree with the idea that America could benefit with a widespread religious revival. However, if the revival revives radical religion, the radicalization will lead to an ugly end. Radicalized religion does not bring people along a road to enlightenment. Radicalized religion brings people along a dark road of division, dispair and increased conflict.