Wouldn’t this argument be equally valid for any President who failed to show their birth certificate? That would be, like, all of them.
We don't know about who did or didn't since this amendment was passed (1933). The list would start with FDR, then Truman, Eisenhower, Kennedy, Johnson, Nixon, Ford, Carter, Reagan, Bush I, Clinton, Bush II, then "you know who". How many of these were there questions about? How many of these were certified as eligible in accordance with section three before being allowed to serve? That would be a good thing to research. Hard to change things from back then, but that doesn't mean we have to allow it in a current fashion. My primary point is that we KNOW what we are presently dealing with and we KNOW that there is a Constitutional remedy available to end it.