I find the whole notion of "transcending race" to be rather pathetic. Michael Jackson transcended race. Michael Jordan transcended race. Etc. Often the phrase is delivered as an accolade, as in "Barack Obama was so good that his popularity transcended race".
Whatever . . .
All this means is that the particular African American had dialed down their blackness in a way that white America wasn't threatened by it. In other words, this means that they were sufficiently white - perhaps not in looks - but in manner and approach, that the fact of their blackness was no longer offensive.
Is that really an accomplishment?