Friendly reminder that Ronald Reagan was called senile so often it became a running gag on SNL and the late night shows. He then won 49 of 50 states in the 1984 election.
This is true, but only because no president will have any desire to try. I think a lot of people forget that Biden was extremely popular for his first 100 days
well for one you don't actually need to, he's at ~40% favorability right now; the best way to win an election is to appeal to those who don't have a candidate yet
that being said if you do want to appeal to trump voters he's winning on every issue except abortion right now so he could work on that