Accounts of unfavorables on both sides of the political aisle have been documented, and part of the dissatisfaction that the Democratic voters have had with Clinton is her more moderate approaches to policymaking. In truth, her policies vary only marginally from those of Sanders, but she has the more pragmatic and admittedly less "sexy" approaches to these political problems -- wear and tear in the Senate and other offices have given her realistic expectations -- which Sanders supporters have ben keen to characterize as being less progressive.
There are a few realities with which they must both contend and one that only Clinton must contend. First, making radical changes at the national level may founder, leaving the Democratic Party highly vulnerable in taking the fall in the 2018 midterm elections. But that would be an unlikely scenario to arise because it is contingent upon even getting to the implementation stage. Which brings us to the second problem. Having a likely still divided government scenario (the Democrats will assuredly move the Senate median to the left, but not necessarily enough to gain control) requires some measure of compromise and conciliation which is hampered by designation as a self-described socialist, and by the stubborn promotion of positions too far to the left and too uncompromising to garner needed moderate Republicans' support.
The Clinton-specific challenge is that of being a woman operating in a man's world, and thus needing to appear stronger, tougher, more in command, and let's face it, deal with slanders that our culture rightly abhors in the racial context and yet somehow accepts in the analogous cases where gender is concerned. Such is consistent with years of American history, with African Americans gaining suffrage far earlier than did women of any color. And concessions to emotion by women immediately confirm biases that women "may not have what it takes" to be the leader of the free world. There is no question that if Nancy Pelosi cried publicly as much a did John Boehner, we would not have heard the end of it. Boehner got a free pass, except for his name of course.
Part of what we are seeing in Hillary is her effort to play this man's game, but until we change the gender dynamics of the United States, it will be a necessary evil, and a necessary condition for winning elected office not to mention prevailing in bargaining conditions upon electoral success. In a wonderful "West Wing" episode titled "Let Bartlett Be Bartlett," in which the main players choose to set loose the progressive Jed Bartlett with whom they had all fallen in love in the primary campaign. Hopefully one day we will be able to "Let Hillary be Hillary," but as long as she and her staff know well, you have to play the rules of the game in order to get in the door and begin to win the real fights. In the meantime, I hope that the Democratic voters have the patience to let her show her true colors as a bona fide progressive and champion of rights as Madame President. We just need to elect her first.