Suspicious letter in PROJO smearing Bernie Sanders campaign as racist

I question the authenticity of this letter . Just who is Stephen Silvia of Providence ? Does he operate out of a Hillary for President campaign office ? Is he a person of color ? Not much COMMENT history.
And who am I to question his integrity ? Well just browse my blog .

 "   Lately we have heard Bernie Sanders complain about his voters' being disenfranchised through an undemocratic primary system and the role of superdelegates. We have heard his followers complain that the elections are somehow rigged, or that Hillary Clinton is winning only because she is the chosen one of the establishment.

But we know why Bernie Sanders is losing. It is because of how poorly he does with minorities, particularly with African-Americans. Never in my life have I seen a Democrat do this poorly with African-Americans. And the worst part about it is Sanders is either oblivious to this fact or he doesn't care.

Sanders has been in Congress for over two decades. Did he really think he could get the Democratic nomination by ignoring African-Americans? Not only will this strategy cost him the nomination, but it also makes people think his campaign is infected by a "white privilege" attitude. "

Stephen Silvia