Historical precedent suggests they only show up for black executions. There's not been a lick or hair of a celebrity or race hustler (Al or Jesse) for the next execution in CA (coming in a few days) and he's a feeble American Indian.
If these "civil rights" leaders really want to prove they oppose the death penalty, they will show up en masse to protest the executions of the slime who lynched James Byrd. I'm not betting that will happen, however.