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The person has to be completely removed from the span of control.
Unfortunately, this is not like being extricated and deprogrammed after leaving a small cult. Most Trumpers live in an are that is Trump country. Their family, neighbors, friends, church congregants, people in town and in the stores and restaurants, are all Trumpers. They can never really leave Trump to regain a sense of self. The community they are living in determines that. Most can not make a clean break, and won't. Their family that would normally perform the kidnapping and relocation to an undisclosed house where family love-bomb them back to counter the cult's love-bombing doesn't exist.
Religious conversions typically come at moments of undue and overwhelming stress, grief, or feelings of loneliness. Many cults operate at colleges, because that is often the first time students are away from their families, in a strange environment and subject to unchecked influences. They prey on people from fractured households or with no friends. It starts slowly, and the target is filled with a strong sense of self-worth and community and that makes them want to initially stay, and then afterwards, they slowly get assimilated into the cult. They would need another type of conversion to leave, or complete removal from all strings that connect them to the cult influence.
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