Purple Skies Above
A point regarding the challenges around the identity politics and identity polemics that are so prevalent at this moment.
It is impossible to prove a negative. If asked to prove that I don't believe the sky is purple all the time, I can point to the heavens above all day long but it won't suffice to actually disprove the hypothesis that I'm a purple sky'er. And nothing I say or do will be enough to wipe clean the tarnish of all the associated perceptions people hold about purple sky'ers. Even if those assertions are plainly absurd on their face ("Purple Sky'ers are racists;" "Purple Sky'ers don't care about homeland security;" "Purple Sky'ers kidnap immigrant babies to sacrifice on altars made of jicama and recycled Ford Pintos believing this is the only way to secure work in the data mines.") - I can't prove things that I am not. Because someone can legitimately (if annoyingly) claim that my saying I'm not something isn't proof that I'm not that thing. Even providing evidence of my good deeds is not sufficient to establish the things I am not. I can only provide evidence of the things I claim to be. Worse, even saying "I'm not a purple sky'er" connects me to the purple sky'ers and all the associated judgements applied to that group in the minds of others. (Hence the continued stickyness of assertions that President Obama is Muslim, or wasn't born in the US).
Yes, this can be maddening. It is frustrating because it leads people into drawn out ideological battles without any hope of claiming victory or getting people to change. But (and I would hold this is the deeper issue) is gives rise to a kind of powerlessness.
If nothing I say or do will get you to concede that I'm not a purple sky'er, then I can begin to feel powerless to assert my own identity. That sense of powerlessness can give rise to a lot of negative feelings and behaviors. It can also drive a kind of tribalism. People who share certain experiences of powerlessness congregate and identify with one another because it helps provide safety and security in what is perceived to be an unsafe world. This tribal clumping leads to the development of shared narratives borne from how people within the tribe perceive the world. These in-group stories are not sufficiently influenced by information from outside the group. Thus confirmation bias and a kind of intellectual incestuousness drive the development of distorted us vs them narratives that become harder and harder to uproot.