Under party rules, each candidate was supposed to vet their delegates. The fact that Sanders refused to this does not surprise me given the delegates who came to the convention.

The Clinton campaign carefully vetted their delegates. Sanders was supposed to vet his delegates but the only vetting I saw was at the Texas State Democratic Convention where a Sanders delegate was duly elected by his Senate District caucus but removed by the Sanders campaign because the delegate would not state that he hated Hillary Clinton and was replaced by a BOB.

Again, Sanders did not come close to doing everything in his power to help the Clinton campaign or the party in the general election. Sanders was weak with his delegates because he did not want to hurt their feelings or do anything that might affect future book sales