Fucking This.
Let me spell this out for that particular junior member.
Minorities have had white politicians floating in promising them the moon since before the civil rights era, and the vast majority of said politicians are full of shit. Naturally, minority voters- especially black voters- are extremely skeptical whenever a politician says anything. Clinton gets a free pass because not only was her Husband an extremely well liked president by the black community, but she worked within the Obama administration and is widely viewed as obama's preferred candidate.
Speaking of Obama, Black Voters were skeptical of HIM as well and backed Clinton right up until Obama proved he wasn't Jesse Jackson 2.0 by getting white voters to carry him to victory in Iowa.
Bernie's entire rhetoric of "dismantle the banks", "free college", "revamp the tax structure", etc etc has been met with a resounding "oh yeah? how?" from every single minority voter I can think of, and there is not one single valid explanation as to how any of what bernie wants to do gets past a republican congress.
Until he manages to prove he's more than just talk, he's going to strike out with minorities as he has been for months. As it is, Bernie's rhetoric isn't any more realistic than Trump claiming to put up walls to keep out mexicans.