A reader writes:
When you said that "no black person could be a Mormon," that isn't factually correct.
Until 1979, blacks could become members of the church, it's just that black men couldn't hold the priesthood, something that all male members of the church about age 12 (I think) are allowed to hold. From 12-18, you are "ordained" into the Aaronic priesthood as a deacon. At 18, you join the Melchizedek priesthood and become an elder. Because priesthood membership is required to participate in most of the church's important rituals (marriage, temple work, etc.), black people were shut out of full membership. It wasn't even second-class citizenship -- more like seventh- or eighth-class.
And the Mormon church also opposed the civil rights movement. (Romney's dad was an honorable exception, and he backed King despite severe pushback from the Mormon authorities). They are consistent in opposing the civil rights of others deemed inferior by their religion.