'He wasnt doing very good'? Did you miss this thread:
https://gbatemp.net/threads/so-amer...candidates-drop-out-at-specific-spots.559323/
The way americas preelection system works is, that you need at least two centrist candidats, seriously wanting to compete for presidency, or you have no chances as a non establishment candidate.
In this years race four centrist candidates dropped out at the most opportune point for the remaining one to cash in their embasador posts and alike.
Its fixed theatre. And this year it was solely decided by when two other popular centrist candidates dropped out and who they gave endorcements to on the same day. (Right before most electoral votes are available, and at the right point - where this is still able to snowball. Because of the most assanine of voting systems - banking on more people seeing and being able to act on 'herd popularity'. You dont ask them a question, and then let them vote in secret - no, you ask them "who is popular" - and then stage events meaning to underly their popularity - while voting is still going on, and then you look at who voted already and tell the rest - well they think - they were about - this - popular, now who do you want to vote for.
The system is fixed - so if you can coordinate, and if there is no 'quarrel' between two viable frontrunners - only centrist candidates win.)
And let me specify this - for absolutely no publically available reason. We dont know why everyone suddenly decided that Biden would become the most viable candidate.
Even media struggled immensely to contextualize any of it.
In the end they went with psychobabble. ('Biden had electability'.) Thats roughly the same as saying, that Jesus is love, and your body and blood. Means absolutely nothing - but stops your rational thought process, if you werent expecting it - and works flawlessly to convince people that can be convinced by suggestion alone.
(The majority of people doesnt want to understand something, they just want to know what the majority thinks, and then copy what they say. So 'electibility' it is.)
Sanders went from 'frontrunner' to 'no chance' in a day - without political reason given, reasoning, or any remarkable speeches, simply because people coordinated when two more likely candidates than Biden at that point, should drop out, and whom they should support.
If you think for a minute - Sanders went toe to toe with Clinton in the last elections, and only lost by a narrow margin after the DNC pulled all strings available. Biden is a guy that was picked by someone who needed a Mike Pence. Why is Sanders all of a sudden less 'electable'? Because someone said so?
Well - what was their (hopefully political) reasoning for that?
There was none. Oh, I understand...