The talk of this by the Left is them simply setting the stage and getting the stupid all riled up. Tomorrow, both need to be asked “If the Election Night results are MASSIVELY in favor of one or the other, will you accept the results?”
No one has asked Biden the question they asked Trump.
That is because, thinking rationally, dispassionately, and apolitically, it is a more relevant question for the incumbent who controls all the levers of power. Not for a challenger.