Honestly, from a pure tactical standpoint Hillary running again isn’t the worst move for the D’s. Not the greatest, but not the worst.
Short of the economy collapsing, no D can win in 2020. Anyone serious about the presidency will not want to be the nominee... serious players will either sit out, or simply use running to set the groundwork for a national campaign in 2024, but will bow out long before they would be the actual nominee because they don’t want to have the millstone of a bad loss to Trump in 2020 to overcome later.
So the D’s nominee in 2020 will simply be a throw away, it will be a back bencher or a past their prime has been... their role is not to win the White House, because they know they wont, but to keep the D voters engaged to help the down ticket races from becoming a slaughter as well... by motivating the base to turn out.
Hillary wouldn’t be my choice for that role, but she could play it...
With all that’s said, I highly doubt she is running no matter what’s the rumor mills claim
Calling past his time Joe Biden?
Would be fun watching him tool around with his foot in mouth problem.