I always thought the "socialist" label was the kiss of death in US national politics, but Sanders had a large and enthusiastic following. Regarding 2020, the way the Republican machine is beating up on Elizabeth Warren and mocking her as "Pocahontas", it would seem the R's regard her as a top contender, so they're doing a lot of advance smearing. Maybe Trump can pull himself out of the hole he's dug, who knows?