The argument was that Sanders was not good at bringing people together when in fact he was the one who brought the most people together. Now you've chosen to shift the goal posts to "people of color", well...
He brings them together, too. Sanders has a 100% rating from the NAACP, indicating a strong stance on racial justice. He has a 95% rating from the ACLU, indicating a strong stance on social justice. He has a higher approval rating among African Americans than any other racial demographic, his approval among white people comes in at around 52%;
The one and only metric critics can point to to try to justify the claim that Sanders doesn't do well among African Americans and minorities, despite all the contradicting evidence, is the 2016 Democratic primary election where Clinton received more votes from African Americans than Sanders. Critics dishonestly ask why didn't African Americans vote for Sanders over Clinton if they support him so much? The answer is pretty simple; Clinton had high name recognition among African Americans prior to the election because her husband was popular within the black community. Sanders was a virtual ghost within the African American community prior to 2016.
That's not the case anymore.. Sanders is widely known and respected among the majority of the African American community, now, as his poll numbers reflect.
So it's pretty sad to see people who claim they want to implement progressive positions in government shit on the strongest candidate who can actually accomplish that. Compounded by sleazy, half thought out arguments that imply Sanders is racist after having spent a lifetime fighting against racism, to the extent of putting himself and his own freedom on the line and being arrested for it. Anyone who pushes this narrative created out of spite is further harming the progressive agenda thereby further damaging our democracy. They will justifiably be held with the same contempt as Republicans who wish to damage our democracy.
That poll you posted is a year old. In any case, opinion polls are terrible predictors of how people will vote.
Bernie screwed the pooch last week. He confirmed all over again to those who didn't vote for him why he wasn't chosen for the nomination in 2016 and what they can expect from him in 2020..
So, back to your theory that Clinton had high name recognition and so the stupid blacks voted for her instead to whom you claim should have won. Name recognition. If that's the reason that explains why stupid blacks voted for Clinton, are you saying that white men aren't stupid like those blacks? Also, let's not forget, the majority of Mexicans and women also didn't vote for Sanders. So, they are all dumb too. Not white men, they are better informed and more rational than everybody else, I guess. Dude, your excuse reeks of white male entitlement.
You look for excuses when the facts are in front of you. The reason Sanders did not poll well in 2016 and won't poll well in 2020 is right in front of you in the recording of Sanders performance on 4/4/18, when his campaign died.