If you are asking which Democrats will run in four years for 2020 to challenge Donald Trump, I would not be surprised if Hillary Clinton runs one last time, if she is still healthy. She has made it her mission to get into the White House and two failed attempts won't stop her from trying again. I could also see people like Joe Biden and Elizabeth Warren running, and maybe even Michelle Obama. I don't think Bernie Sanders will run again, because of the corruption in the DNC and his advanced age. He will be closing in on 80 years old, when 2020 rolls around.