The Religious Void

[Mister Agenda]

As you seem to recognize, the tendency of American Evangelicals to believe anything Trump says despite any factual evidence otherwise and to also be antivaxxers suggests to me that at least for that particular subgroup of Christians, their religion does not inoculate them at all from political cult-like behavior.

I'm curious as to why you included antivaxxer in your description. Insofar as any Christian is an antivaxxer,  the reasons for it seem to align with my theory. It is an over-allocation of trust in Christianity, that leads to a deficit of trust in other entities such as science or governments. My guess is that any overlap that might exist between them and Trump supporters, is likely due to Trump championing a mistrust in science and government, despite him being in government.

Is it better to have a well defined religious structure in which religious activities can exist rather than no structure at all; and does that successfully diminish religious behavior elsewhere?

You posed the question whether a well defined religious structure diminishes religious behavior elsewhere. It seems not.