Not only does fundamentalism promote delusional thinking, it also discourages followers from exposing themselves to any different ideas, which acts to protect the delusions that are essential to the ideology.
How Religious Fundamentalism Hijacks the Brain | Psychology Today
Of course, it would be irrational of magical thinkers to pursue policies that were not supportive of their own theological fictions. They’re brainwashed to support their own delusions, of course, because God told them. It’s a circular argument.
The only problem is that their endorsement of a candidate who is hypocritical actually endangers their belief system in myriad ways. That they cannot see the threat to their belief system from his policies and acts is astounding.