The American constitution was written by Calvinists. These were Madison and his friends.
They were concerned about limiting government and they wanted a separation and balance of powers.. Why? They knew something about the human heart.
Strict Calvinism historically has not lasted long. Puritan Massachusetts inevitably gave way to Unitarianism as the people rejected Calvin’s rigidity.
The similarities between rigid orthodox Calvinism and Islam today can be found in the writings of people like Rousas Rushdoony’s Institutes of Biblical Law and in the Christian Reconstructionist movement.
http://www.patheos.com/blogs/unreasonablefaith/2009/05/r-j-rushdoony-reconstructionist-and-racist-bigot/
The parallel between Islam and 16th and 17th century Calvinism can be found a)in their rejection of the role of human reason in faith and revelation b) in their understanding of God’s sovereignty c)in the rigid application of Old Testament law.
Islam knew a period in the early Middle Ages between the roughly 8th and 10th centuries when a group known as the Mutazila promoted an Islamic theology that accepted the role of human reason in faith.
http://en.wikipedia.org/wiki/Mu’tazila
But they were overpowered by Asharites who said that human reason had no place in theology just like the Calvinists did in their rejection of the Catholic Church.
http://en.wikibooks.org/wiki/History_of_Islam/The_Mutazilites-Asharites_debate
The irony here is that St. Thomas Aquinas and the scholastics were influenced by the Mu’tazila when they brought Aristotle’s thought into Western Christianity.
The Asharites, who were the predecessors of modern Islam, held a similar view of God’s sovereignty to that of John Calvin to the point of saying that if someone was killed. It was God who killed them.
Scholars have also noted strong similarities between John Calvin and Muhammad ibn-Wahhab due to their strict puritannical ethic.
http://books.google.com/books?id=EEEFsVYLko4C&pg=PA98&dq=wahhab+calvin&hl=en&ei=tbvmTs_bIMrf0QG3msH7CQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CDAQ6AEwAA#v=onepage&q=wahhab%20calvin&f=false
Calvin and his followers destroyed Catholic temples and the relics of saints. Wahhab and his followers did much the same. And both were theocrats.
http://books.google.com/books?id=WfGSzKDvh8IC&pg=PA119&dq=wahhab+calvin&hl=en&ei=tbvmTs_bIMrf0QG3msH7CQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDYQ6AEwAQ#v=onepage&q=wahhab%20calvin&f=false