Now, you have to throw out Zero. He was sui generis. There will never be another Obama because there can only be one “first black president.”
Except Obama was a middle/upper class kid from Hawaii and had Kenyan father. That is as far as you can get from an authentic black American experience. He does not have slavery in his family tree. Other than his white mother, of course. The first more typical black experience candidate will resonate just as much as the kenyan, unfortunately.
Resonate some, but not as much. You got plenty of White people voting for the first Black president thing who aren't going to be voting for the second or third.
Gillum, from what little I know of him, is probably more authentically Black than Obama or Harris or Booker, but I don't see him attracting the level of support that Obama did if he ever runs for president.
Also, the bad 2008 economy had a lot to do with Obama winning.