TBF, what white politician can you name that has a better "race relations history"? Honest question. I think the few that are looked upon as having good relations with
The Black Community™ all have racial skeletons in their political and/or personal closets. When Obama chose Biden as his VP candidate, there were collective groans from many Black people and progressives. Some deemed it the end of his candidacy. Once they won and he served in office under Obama, effectively becoming his pit bull, Biden's bonafides were established in the minds of many African Americans. They never thought he was perfect. That he redeemed himself (at least partially) given his past record with what he was doing to put forth Obama's agenda. It helped given the rise of Birtherism. Who knew calling the country's first Black President a Kenyan would turn off Black voters!
In 2008/2012/2016 the alternative was far, far worse: Black voters were not going to vote for McCain/Romney/Mango!!!