Obama while retired still has a lot of sway in the party. He had a lot to lose politically if Bernie ended up making Obamacare look like the joke that it is. Furthermore we know from 2016 wikileaks that the donors are very adamant that if they didn't stop Bernie then they might as well not call them ever again for money. I'll never forget the leaked voicemails that had donors literally screaming at Democratic leadership to stop Bernie at whatever cost. Looking back, while Bernie's team did a superb job in 2020, I should have realized that you cannot beat a system in which the other side controls the strings.