i think it's definitely in the realms of possibility especially if this latest episode for Hillary effects her 'media' image and gives a significant boost to Tromp.
in which case if H drops out then Biden would take her place and Tromp would look more like the President, of the USSA.

in which case perhaps the scenario you outlined here may occur, however there is of course an 'infinite' vector of possibilities.

and it seems 'these days' one could throw a dart and hit a 'bad thing' someone said :

"There are a lot of Ravens outside a lot of people windows."

then someone else said :

"so what? Ravens are birds that's what they do hang outside windows."

ha ha.