“I believe that FBI agents, perhaps the director himself, James Comey, will resign and President Obama will be confronted during his last six months in office with a crisis not unlike Richard Nixon’s during the so-called ‘Saturday night massacre’ in Watergate where people resigned rather than doing what the president asked them to do.”
According to Napolitano, “that will have a catastrophic effect on Mrs. Clinton’s candidacy. Probably so catastrophic that she will be replaced on the Democratic ticket.”
I don't have TV so I never see this garbage, but it looks like the quote you posted says that it was his belief, not a fact.
I have an open mind if you can point me to info that says otherwise.