When I met Rachel Dolezal, I found it easy to accept her description of her ethnicity. Along with BBC correspondent Jonny Dymond, I talked to Dolezal in 2011 in a coffee shop in Spokane, Washington, while producing a BBC World Service documentary on a surge in extremist militia activity in America. She told us that she was of mixed racial heritage but that she primarily identified with her black ancestors. She matter-of-factly listed the abuse she says she received at the hands of racists, including threats, break-ins, and nooses being left at her workplace. At no time during our hour-long...