This letter was published at electoral-vote.com today, and it introduced some useful methods to consider whenever you are trying to persuade anyone, but particularly trying to persuade someone who holds untrue beliefs.
It would be interesting to discuss the psychology of how to break through the mind traps that people get themselves into.
"You can't reason a man out of a corner that he didn't reason his way into."
A.C. in Aachen, Germany, writes: Being into social psychology quite a bit, I very much liked your overview of the theory of cognitive dissonance in response to the question about why Trump's support is so consistent with his base. As the theory is so influential (more than 1,000 studies over the decades), I would like to add a few aspects and widen the scope of the answer.
You talked about how dissonance might be reduced, but I think this deserves a closer look. Festinger (who developed the theory) assumed that people use the path that requires the least change of affected cognitions. There are basically three ways to reduce dissonance:
Addition of consonant information, e.g. finding ways to support the decision (he appointed judges, cut taxes, owned the Liberals etc.)
Subtract dissonant information, e.g. weaken the notion that Trump is a moron (smear campaign, liberal hoax, witch hunt, biased media, ignoring or not perceiving facts etc.)
Change of behavior, which in this case would mean not to favor Trump any longer and probably not vote for him again.
Given the high level of commitment in a very polarized elecorate, it's plausible to believe that many voters will not chose the third path, as the number of cognitions to be rearranged would be quite high. It demands much less cognitive effort to follow the first path, the second path, or both.
That said, the theory also suggests that different outcomes might take place depending on what lines of attack are used during the campaign. It doesn't make sense to reach out to hardcore Trumpers; for them the change in the cognitive system is far too large. But independents, old-school Republicans and Democrats who voted Trump in 2016 might well be persuadable. For them, I think the challenge is to frame the message in an way that allows persuadable voters to change to the Democrats without having to change cognitions too much. "Trump is an idiot, you see it yourself, and we told you all along" would not do the job. On the other hand, something like "we understand that there might have been reasons to vote Trump then, but we got your message, we changed, its okay to vote Democrats this year." Of course, this messaging would cause dissonance for the progressive wing of the Democratic party, but there is always some amount of 3D chess involved.
V & Z respond: The term that many commenters use these days for this way of thinking is "permission structure," and it's clearly the basis of what the folks at the Lincoln Project are doing.
It would be interesting to discuss the psychology of how to break through the mind traps that people get themselves into.
"You can't reason a man out of a corner that he didn't reason his way into."