Citation needed on "The idea is that an increase in secularization associates with its decline." This certainly is not the majority opinion of historians, and it's certainly the first time I hear anything like this.
They make sense to me.
How is something making sense to you different from it making sense to everyone else?

I've posted about this in the past. Getting somebody to associate an idea, person, or event with an image is a more powerful way to influence what he or she thinks about the idea, person, or event. It's a tactic that Trump is fond of using.
Fair enough, but what pictures of what event is he referring to?