Opinion changes about grand things like a political doctrine may be difficult precisely because the opinions themselves are inconsequential. If I mistakenly vote for the party A instead of the party B, there are no personal consequences (my vote won’t change the outcome). By contrast, if I change my mind there are at least two negative consequences:
1) My ego will be hurt (I’ll have to admit that I was wrong before)
2) My friends and colleagues will be annoyed with me (statistically, friends and colleagues are likely to vote for the same party)
Political beliefs can cluster with more consequential behaviors than voting. For example, consider the relationship between views on economic policy and the appeal of different careers (or fields of academic study). Or political views and religious behaviors. Or the subjective appeal of living in Texas vs San Francisco. Knowing humans, there probably isn't a clear direction of cause-and-effect.
Anecdotally, I've changed my political views recently, and I'm surprised by the breadth of the associated cluster of beliefs (some of which are non-socially consequential) that shifted at the same time.
Our beliefs aren't just cargo that we carry around. They become part of our personal identity, so much so that we feel hurt if we see someone attacking our beliefs, even if the attacker isn't speaking to us individually. These "beliefs" are not necessarily grand things like moral frameworks and political doctrines, but can also be as inconsequential as an opinion about a song.
This post is for discussing times when you actually changed your mind about something, detaching from the belief that had wrapped itself around you.
Relevant reading: The Importance of Saying "Oops", Making Beliefs Pay Rent