I honestly wonder if anyone in the Democratic Party tried, right at the start, to talk Clinton out of running. "Don't do this, Sec'y Clinton. If you run, half the country is never, EVER going to vote for you and the press will spend the entire time reporting on 'troubling' revelations about you. And we NEED to win this. Please don't burden us with your baggage."
Probably such a conversation never happened. There was no one who could have told Clinton, "Don't," and kept their job.