[boplicity]

There's no unified group of white people who want to be called White as opposed to white. Though, maybe I'm wrong? Is there such a group?

[estebank]

There is such a group, but they usually pair "White" with some other word that implies superiority.

[boplicity]

Ha -- I think in that case capitalization makes sense -- especially when the words are paired -- as this at least does some work to make the group identifiably separate from those who do not at all identify with them.