Everything you typed is true and valid and yet 11 days out Sec Clinton held a large lead in national polling .... some would say insurmountable .... and then the bombshell. Within days her large lead evaporated.
None of the reasons mentioned, taken singly or in concert, explain the rapid drop in her polling following Dir Comey's re-opening of investigation.
Of course thus could have been a coincidence and not causal ... so why not mention it????