Ignoring that I never said anything about Sanders supporters defecting (which, by the way, while it is true that fewer Sanders supporters defected, 2016 was a much higher stakes election and had a lower turnout than 2008, so that's stuff to consider, as well), I would almost wager that a good number of the people who stayed home, defected to Trump, voted third party, wrote in Sanders, etc. did so because of Republican smear. I mean, people argue that Comey sabotaged the election with his "we found more e-mails" a week before election day. Again, the big reason Clinton was so unpalatable to so many people in the first place, regardless of political affiliation or views was Republican smear. Obama was also heavily supported by corporations, as is virtually every major politician (obviously with Sanders as a major exception), to say nothing of being upset at a Democrat being a corporate shill when the Republican party exists.