[Question] Probability that the President would win election against a random adult citizen?

Suppose we magically intervene on the USA to make there be a snap election for the office of President. The incumbent (the existing president) goes up against X, where X is a randomly selected eligible person (e.g. adult, citizen, etc.) Voters have one month of campaigning before they decide, so X isn’t a total stranger by the end.

What is the probability that the President wins?

Is the probability substantially different for Biden than it was for Trump? What about Obama?

What is the probability that the President loses in a massive landslide (getting e.g. only 40% of the vote or less)?

ETA: I’ve changed the title to stop giving the impression that I am looking for a yes or no answer. I’m not looking for a yes or no answer, I’m looking for a probability.