I have nothing major or even troubling against HRC. Perfectly sound mainstream Dem with good political instincts and God's own Rolodex. But there's nothing about her that makes me driven to support her personally. It's kinda cool to get a female POTUS, a generation or two after most major democracies though that is, and I respect the machine she and Bill built, but as a person and campaigner she's a bit dry and uninspiring, and as a policymaker she's hardly devastatingly original or exciting. I'm voting for the D because I don't want any R, let alone just Trump, anywhere near any seat of power. I'll donate and campaign a bit and vote for Clinton in exactly the same way as I would if she had to drop out and Biden or Gore or Kerry stepped in. No more no less. Sanders was a bit more original and inspiring but not to a life changing level to be honest. I never saw the huge gulf many of his more rabid supporters, or distractors, did.
I however don't think that's a problem. We have two viable parties to choose between. I have some quibbles with any Dem but nothing sine qua non. Reps on the other hand should not be allowed any authority above traffic control and that only under supervision. Every vote I make is against Reps, and for Dems only in that they have a more sensible philosophy. The last individual I thought moldbreeaking enough to vote for them personally rather than as a D standardbearer was Paul Tsongas against the last successful Clinton primary run in 92, with expectedly zero impact. I was happy with Clinton, B. and expect to be happy with Clinton H., but I'm not voting for either as a person but as an adocate for the only sound theory of governance available to us.