As for 2020 candidates some possibilities come to mind-
Bernie- would generate excitement and get blue collar vote back, but he's old not sure he will try again
Elizabeth Warren- another progressive like Bernie but not sure the country is ready for a woman as sexist as it sounds
Corey Booker- young and promising face in the Democratic Party
Michelle Obama- this excites me the most but she doesn't want to get into politics but that could change with Trump.