the modern descendants of early Calvinists. While it's true that Calvin and his early followers, like John Knox in Scotland, promoted "true" Christian communities governed as a theocracy based on predestination, the theocracy idea died out gradually when exposed to the reality of living among various other Christian denominations in the American colonies and in Europe.
The doctrine of predestination associated with Calvinist denominations is not exclusive to Calvinism. It began in Roman Catholicism with the theology of Augustine (354 CE/AD to 430 CE/AD). Predestination theology continued in the Roman Church through the order of Augustinian monks to which reformationist Martin Luther belonged before his excommunication by Pope Leo X.
Not all Protestants have their origins in Calvinism. Lutherans are not Calvinistic. Anglican Curches are neither Roman Catholic nor Protestant, but a sort of Anglican Catholic, minus the Pope but plus married clergy.
Methodists are not Calvinist.
Descendant denominations of Calvinisim are Congregationalists, Baptists, Mennonites, Amish, Reformed Churches (I.e. Dutch Reformed), and Presbyterians, and a few others.
Many modern Protestant denominations have subdivisions that have evolved over disagreements about practices and doctrines. That's true of Lutherans, Presbyterians, Methodists, and Baptists. Even Roman Catholicism has its ultra conservstive, orthodox members and more liberal members.
Among some Calvinist churches, election and predestination have been redefined as love, acceptance, and grace available to all.
This is based on theological principles of the early 20th century Swss Reformed theologian, Karl Barth. Barth was a founding member of what was called the Confessing Church in Nazi Germany. The Confessing Church opposed Nazi infiltration of German Protestant churches which promoted German Christian Nationalism. Barth, who was a professor at a Bonn university, wrote out his principles and mailed the document to Hitler. He was then fired and forced to leave Germany. Two of his Lutheran clergy followers, Dietrich Bonhoeffer and Martin Niemoller, became well known for continuing Barth's views in Germany. Both were arrested and put in concentration camps. Niemoller survived. Bonhoeffer was executed.
Catholicism is not immune to Christian Nationalism, which merges religion with right wing absolutist politics. Prior to the Reformation, the Roman Catholic Church was the most influential political body in Europe, having power over monarchs and governments. During the Spanish Civil War, the Catholic Church sided with Franco's far right dictatorial challenge of a democratic government.
In the US today, right wing Evangelicals and conservative Catholics overlap as allies in their efforts to enforce religious doctrines as secular law. Christian Nationalists are a separate but related group who also wish to enforce religious doctrine as secular law, but in addition, they are racist White supremacists.
One more word about Calvinist churches. My OP mentioned a pastor's letter of concern about Christian Nationalism. He later gave a sermon that strongly condemned it. This was in a Presbyterian church with roots in Calvinism.
= new reply since forum marked as read