Sanders hasn’t lost much support among his most avid supporters. What we are seeing, however, is that it’s no longer taboo in liberal circles to attack Sanders as he drags out the nomination process at a time when many are itching to turn their fire on Donald Trump. And if his reputation in the party is being damaged outside his base, that will make it harder for him to extract concessions from Clinton regarding the platform and party nomination rules at the convention.
http://www.politico.com/magazine/story/2016/05/bernie-sanders-loses-his-halo-213911
