You can’t make a plausible argument that Sanders is more qualified to be President than Clinton, so the only reason to vote for him is his agenda. The agenda, in turn, has no future unless millions of disaffected voters can be persuaded to vote, not just for Sanders himself, but for left-wing Democrats at all levels of government. Hence, the need for the “revolution.”
The Sanders campaign scrupulously adhered to this approach in its early days; most notably, he declined to comment on the Clinton e-mail issue, because he knew it wouldn’t advance the “revolution” in any way. Now, however, in the face of levels of turnout that prove that the “revolution” simply isn’t happening, Sanders is starting to become less of a “revolutionary” and more of a conventional left-wing Democratic candidate. He still isn’t saying much about the e-mails, but he is taking shots at Clinton for actions taken by her husband in the 1990’s, among other things.
None of the new attacks on Clinton are personal or gratuitous, but they don’t advance the “revolution;” they are only designed to get Bernie elected President, which isn’t going to happen. If Bernie is really serious about the “revolution,” he needs to change the focus of his campaign to encourage votes for Democrats who share his agenda at the congressional and state levels.