And there's the problem right there.
The Constitution is a ground breaking document. Just because it did not hit a grand slam home run in terms of fixing all social ills in one fell swoop doesn't mean it's "rife with racism and sexism". It established the fundamental mechanisms that would enable us to progress as a society despite individual shortcomings and faults. And we have - often at great cost.
It is those same fundamental mechanisms (freedom of speech, freedom of the press, freedom of religion, freedom of movement, ...) that are under attack by power mad elites. Without these mechanisms in play, of course everything becomes much more contentious.