First, progressives never supported Clinton. Liberals apparently do, but progressives tend to be those who are passionately well-informed about politics and policies. They do the research, read, analyze. Hillary Clinton's long public record speaks for itself. She has consistently been a neoliberal -- pro-war, anti-poor, pro-corporate empowerment, anti-New Deal.
Secondly, we know that usually, the VP goes on to run for president. VP Joe Biden will be launching his campaign later in summer. Any Dem pol can then challenge him for the nomination, and the primaries will determine which one goes on to run for president.
Third, America has no agenda today, and there is nothing on which the people can unite, which makes progress itself impossible. We're profoundly divided, rich vs. middle class vs. poor, to the degree that we can't even think about what's actually in the best interests of the nation.