If they replace Hillary, they will replace her with US Senator Kristin Gillibrand from New York.
First of all, there is no way they are going to replace their first female nominee with a man. That simply will not happen.
So you have to look for a Democrat woman of national stature who could win and who would be acceptable to Hillary.
That is a pretty short list. The two California Senators are too old. Hillary would not accept Warren, because she is too much of a star in her own right. Knoblocker has a weird ethnic-sounding name, and is too Midwest. Gillibrand, on the other hand, is young, fairly good looking, and inoffensive. She would beat Donald Trump like a drum.
Kristin Gillibrand will be the next President of the United States. If the Donks pick her, they can’t lose.
Are you on drugs?
I bet 95% of the people in America have never heard of her. Of course, that doesn't matter to Dem voters. "I'm supposed to vote for this Kristin guy? Is that the one from Free Republic? No? OK. Voting done. Several times."