Luckily I don't have to rely on this single article to say everything I have to say about Christianity and religion, since I've written literally hundreds of others. See for yourself through the link below, which will take you to a categorized list of them on the blog I started in 2011. (It's not really a blog but a repository of philosophical articles.)
How do I handle John's high Christology? By saying it's a result of a gradual deification of Jesus, since John's gospel was likely written after the other three, and John's is influenced by Gnosticism which made for his complex, metaphysical speculations about Jesus's identity and relationship to God.
For John, Jesus was one with God in the sense that he shared God's fellowship and his magical abilities reflected his divine origin. But he was also subordinate to the Father as the Logos and Son of God. In the first century, Christians were still figuring out what they wanted to believe about Jesus's identity, so the early texts are confused on the issue.
I don't think it's so mysterious how conservative Christianity could be so Americanized that it became consistent with something as monstrous as Trumpism. Christianity had already been turned into anything you could want it to be. It's been made consistent with slavery, torture, war, imperialism, patriarchy, and capitalist greed. Of course it could also be made consistent with a horrific cult of personality. What does Christendom have to do with Jesus or with authentic religious faith, Kierkegaard might have asked.
I wouldn't blame a mere selection of leaders. I'd look at the emptiness of the minimal Protestant creed.