I think it is fair to say that the Clintons were working to clear the field from the moment Obama took the nomination. From Obama appointing her to Secretary of State to the quick silencing of any momentum behind Warren to the guiding hand of DWS, it is clear that the Clinton were not going to let an underdog upset her again...and yet a severely handicapped Sanders almost managed to do just that.
The fix was in. Granted she is clearly qualified for the role, more so perhaps than any other Democrat. As a campaigner she is horrible and as a leader her judgment is paranoid and questionable.
Sanders was never close if you actually look at the electoral math. Clinton had a much larger lead on Sanders than Obama had on her. After Super Tuesday the election was effectively over.
More importantly, effectively working for institutional support is not 'rigging' the system or if it is then every primary in all of US history has been rigged, which also makes his point useless.
