As I’ve noted on many previous occasions, there is little point in voting for Sanders unless he can also produce the “revolution.” The “revolution” would turn the Democratic Party into more of a working class based party than the current coalition of victims, which is practically impossible unless its leaders tailor their pitch more to the kind of white working men who are currently supporting Trump. That would mean showing far more sensitivity to white rural values, including gun ownership, than is popular with most of the members of the party.
Sanders could have taken a strong stance on these issues. He could have, for example, argued forcefully and consistently that gun control measures are best handled at a local level, because the party needs the votes of rural gun owners. To take the matter to a higher plane, he could have taken the position that racial issues are simply a distraction from the more important matter of uniting the working class to rein in capitalists and Wall Street bankers. He didn’t do any of that, because he knew perfectly well that it would cost him more votes from urban and suburban activists than it was likely to win.
In other words, in the final analysis, Bernie sold out the “revolution” and became a conventional left-wing Democratic candidate because it gave him a better chance of becoming President. He wasn’t going to win in either event, but it would have been a lot more interesting if he had decided to compete harder with Trump for his angry white working class voters.