As much as I would like to believe that the junior senator from New York would see the handwriting on the wall and accept defeat in the Democratic nomination race (full disclosure - I am NOT a Hillary supporter), I have a very hard time believing that this will happen.
All of our experience with the Clinton political machine indicates that when times get tough, the tough get mean. I firmly anticipate smears, libels, outright lies, and quite possibly an attempt to manipulate the entire nomination process (i.e. getting delegates from states that aren't supposed to be allowed at the convention).
If eight years of the Clinton White House taught us anything, it should be that there's nothing more dangerous than a wounded Hillary.