Why can't people change their minds? Why can't people admit that they were misinformed, that upon further consideration and based on new information, their opinions have altered from their previously held positions? Why is this seen as indecisiveness rather than as a thoughtful, methodical process of enlightenment?
Strom Thurmond and George Wallace were able to do that--to rise above their racist pasts, admit they were wrong, wrong, wrong about issue of race, and become viable political entities again. That is regarded as studious and rational. Maybe only right wingers are permitted that kind of self-examination.