Attempt to assassinate Trump will strengthen his candidacy. Democrats seem to be in total disarray and do not seem to me to be able to find a way forward without Biden as their candidate.
I had not realised the extent of the trouble they are in. Apparently if they try to replace Biden with anyone other than Camila Harris they will provoke a massive internal battle.

Speculation that Obama and Cooney want Biden to step down voluntarily hasn't helped because they have not said who should be the candidate in his place.