We cannot explain the whole evangelical megachurch phenomenon on hypnotism. But there is a lot of overlap. It appears that many millions of Christians are partly hypnotized by evangelical preachers who, without conscience, manipulate them.
One characteristic of hypnotism is called trance logic: that is, accepting a logical impossibility almost without noticing it. Usually, when confronted by two situations that cannot both be true, the human mind tries to figure out what happened, struggling mightily to rationalize them. But when a person is in a hypnotic trance, they simply accept both without any mental stress.
In 1959, Martin T. Orne used the presence or absence of trance logic to distinguish between people who had really been hypnotized and those who just pretended. The pretenders tried to explain what happened, the truly hypnotized people did not.
Millions of people, most of them at least pretending to be Christian, believe that Donald Trump won the 2020 election, and that there was massive election fraud. When confronted with the total lack of evidence of any fraud, they persist in their beliefs. That is, the lack of evidence causes them no discomfort whatsoever in their beliefs. This is not something that thinking people do. This is something that hypnotized people do.
This does not offer any justification for what the evangelicals are doing. It is well known that no one can hypnotize you to do something you believe is wrong. The hypnotized people, who resonate with the racist rants of the far right, who desire a far-right dictatorship, and who have lots and lots of guns therefore must believe that taking armed action against the rest of American society is at least acceptable. If they do take up arms to establish themselves as the rulers of what was once the United States, they cannot claim that the hypnosis was responsible for their actions. They really are evil; hypnosis merely facilitates their evil.