People form groups naturally. These groups appear in public, discuss things, and may hold opinions as a group that the members do not agree with. Things like stability and a safe environment are important for people. In public they may conform to the rules that they do not follow in private.
Important members of the group express their opinions in public. They may be the employers in the community. When election comes around they have a big influence on the candidates and votes. The members of the group may follow the leader on some issues or all of them. Personal opinions are not so important to many people. The authoritarian group respects a strong leader.
In addition some of the people voting are not smart enough to follow what happens after election. They actually never find out they were screwed. Or they refuse to admit it out of embarrassment.
Social psychology is the field that attempts to unwind all this and see what the factors are that determine election outcomes. In the internet era you could get a lot of data from anonymous surveys. But they too have error, there is now a reluctance to answer. The internet is seen as too invasive. We just use it to get info, not to provide it.
The topic of the book was quite eye opening for me, as I have never identified with any groups in this manner, other than the camraderie I had as a scientists with my type of science.