No way the Democratic Party will let Bernie be the nomination. It was no coincidence that when Sanders started to pull away from the pack the more moderates drop out and endorse Biden.
If the voters wanted Bernie he would have won more votes. The Bernie / Warren / Kamala wing topped out at about 40% of the Democratic vote (see polls going back a year).
And once the average voter saw that Sanders had a chance they coalesced around Biden. Biden would be a poor candidate even if he was mentally all there (which he isn't) but the party - and the average Dem voters - thought Biden was preferable to Bernie.
I was hoping for a contested convention so I'm a little disappointed. But, there it is.