Following is a discussion on belief revision.
1) One example of a case in which a belief is changed without much thought involves weather. If a person who wants to go outside for a walk is inside near a window and can tell that it is raining, they might decide that they would be better off staying indoors; conversely, if the rain stops, the person might decide that it is alright to go outside for their walk. In this simple example, the person's decision to go for a walk is dependent on whether it is raining. In prolog, this could be expressed as: activity(walk_outdoors) :- \+weather(raining). activity(stay_indoors) :- weather(raining). 2) Convincing someone to change a belief which they somehow identify with is often very difficult. People are vulnerable to cognitive bias, fallacious thinking, and, in some cases, outright delusions. As such, successfully persuading someone to reconsider a belief can be more dependent on your rhetorical effectiveness rather than on how logical your argument is. In a hypothetical world in which none of the aforementioned confounding factors influence people's ability to reason, I believe it would be no more difficult to convince someone to reject their previously held political beliefs in light of new/more relevant evidence than to convince them that the current weather is unsuitable for some activity.