Unless she manages to get well liked again and comes back as an unabashedly angry populist, no.
People get well-liked by not running for office. Also, considering that people weren't in the angry-populist mood in 2016, still got one forced on them, and now disapprove of him, I don't think angry populists will get far at all in 2020.
The main question for the Hillary Clinton campaign (especially for the Democratic primary) is -- in 2020, will most people see her as at fault for the Trump victory? Or as having fought the good fight to stop it? That, more than anything else, will determine how a comeback attempt is viewed.
