Hillary had the lock on the nomination, that for some reason saw only a token challenge, and they lost to the biggest asshole, even as Russia was interfering and Obama didn't say anything because it would look political. After Obama continued the plutocratic rot in every way, the only real reform being the ACA his first year. After that, just slower rot than with the Republicans. Assassinating american citizens without trial overseas, using drones on people in sovereign countries, using the cia to impersonate vaccination workers to get osama, continuing to torture people in guantanamo. Continuing to bail out the rich in 2009, rather than homeowners, not using it as an opportunity to start a wpa type organization or otherwise use borrowed money to stimulate the economy to actually build infrastructure that would save money in the long run and not just hand it to banks, whom are the enemy of working people.
I wouldn't know where to start continuing to list the ways Obama failed the country. We needed a new deal, people wanted reform, and instead we got the status quo, with a radicalized republican party planning on fixing elections, backed by russian intellgence, and we know now, and Obama had to know then, compromised also by Israel. Making a deal to allow an unwinnable candidate back in 2008 to get the nomination after him is a good place to start though. When she dropped out they made that deal, it was her turn in 2016. We needed a leader to spearhead popular reform, and not providing it allowed the republicans to run as reform, and win. Biden obviously failed harder, Obama was at least popular.
Enough allowing the establishment to remain in power, we are doomed to fall under the boot following their lead in case you didn't realize that yet, and anyone telling you otherwise has been wrong about everything. Those ivy league suits aren't on your side, preventing popular reform is their reason for being, not stopping republicans, despite the latter planning on fixing elections and pursuing their opponents with the justice department in manufactured allegations.