One can only imagine the behind-the-scenes maneuvering going on. Really, the only thing Hillary has going for is the threat to take down as many others with her (starting with Obama) if she's brought down. That's the only calculus that will matter between know and the convention. The D angst is whether they can force her out with minimal damage or have to acquiesce to her going down in flames in the general and try to salvage what they can for the next 4 or 8 years under Trump.
I always thought that the Clintons threatened everyone around them - they have all the FBI files, after all, and have probably looked at the most recent and updated ones. Charming couple - sort of like the Goebbels.