I believe so as do many here. But, realize that if Ex-President Trump is re-elected, he will be even older at he end of his term, should he live that long despite his weight, diet and exercise intolerance. Whatever mental deficiencies he currently exhibits will likely only be more pronounced as he ages.
Tit for tat (appropriate for this site). If President Biden’s too old, then why isn't Ex-President Trump? In that age bracket, two years age difference doesn't matter much in terms of remaining lifespan or onset or mental decline.