We're living in historic times, as far as LGBTQ issues and rights go. It thrills me to see the arc of the moral universe bending toward justice. Slowly, but surely, I think we're getting to a world that is more loving and accepting of the widely and wildly diverse examples of the human experience. And I think brave people like Caitlyn Jenner are helping us get there.
I agree that Jenner and all trans and genderqueer people get to claim and express a gender different than the one they were given at birth. I also agree that Dolezal or any other white person does not get to claim a racial identity of color. But I'm struggling to understand why one and not the other, and so far I haven't found an argument that holds.