Look, one of the things the Republicans, or at least Trump, do way better than Dems is get a simple idea, no matter how lamebrained, across to their monosyllabic voters. "Kill Obamacare," "Build the Wall," ""let's win back our freedom to say 'Merry Christmas' again," "the Demoncrats are baby murderers," -- they pound home simple themes that red, white and blue high school graduates can understand.
The lefties as a group are pretty disjointed in their political and social beliefs but I still believe that they can be motivated by a few simple, clearly stated goals. Maybe it's lower the age of Medicare as a first step towards health care nationalization, maybe it's college debt relief, maybe it's something even as simple as legalizing weed. But fer chissakes, have a goal that people can get behind. At least they'll know that you (the Dems) actually want to accomplish something.