I mean, I'm sure there are a ton of black people supporting Hillary who aren't hyper-informed on the issues, who have unrealistic expectations of what she could do, who have whitewashed some of her past politics. But the same could be said of supporters of any candidate.
The EITC, SCHIP, WIC funding, the FMLA, the civil rights bureau of the justice department, the effort to open the military to gay soldiers, the defense of federal AA programs, these aren't nothing. Older black folk mostly remember Bill and Hillary Clinton being on their side during the political battles of the 90's, and generally they're not wrong. It's not to say they didn't fail or concede ground in those or other areas, or that activists should ever stop pressuring elected officials.
But when you're looking to persuade, it's best to try to start from a place of actual understanding and listening, rather that dismissing or pathologizing those you disagree with.