It appears to me that Bernie Sanders entered the race as a foil for Hillary. He missed his big opportunity to hurt her by excusing her from accountability on her emails. He gained in popularity from a start of 6% to over 40% because she is soo flawed. When the revelations of a concerted effort by the Democratic National Committee to prevent him from beating Hillary, instead of raising his voice and crying foul, he released all his delegates in a proclamation of his support for her. Finally, the Bernie supporters are angry not at Hillary, but at Bernie because for the first time they realize he joined the race only to prop her up and make her look like she is capable of winning a fight.