A presidential candidate running against a "popular" incumbent president is more like a virgin sacrifice to the political gods than a political contest.
The smart move is to consider 2020 as practice for 2024.
The betting odds are still about 2:1 in Trump's favor.
Donald Trump (R) -140 -163
Joe Biden (D) +175 +162
That was before last night and since you didn't link your contention, I believe it probably includes Sanders.
Those odds are current, Bernie is toast, here is the link. 2020 Election Odds | Who Will Be The Next US President?