No this is worse.
https://en.wikipedia.org/wiki/French_presidential_election,_2002Jacques Chirac Rally for the Republic (Rassemblement pour la République) 25,537,956 82.21%
Jean-Marie Le Pen National Front (Front national) FN 5,525,032 17.79%
A crazy candidate getting past the primary occasionally due to good luck, cosmic rays, split vote, aliens, whatever is fine. They just need to lose, and lose *big*, in the general. Even if Clinton squeaks through, this will be entirely too close to call when one candidate is
manifestly unfit for office even if you 100% agreed with him on every policy position he takes.
Granted, the French example isn't perfect, since that was a right-wing candidate & a far right-wing candidate, which would be the equivalent of a general election between Mitt Romney & Ted Cruz with no 3rd party candidates allowed, which would probably be a pretty easy win. (Same with, uh, Clinton vs. Sanders in the general election somehow.)