Sanders is a Democrat for all practical purposes. He caucuses with Democrats and his voter base is Democrats. The Republicans have not been absurdly successful

Sanders is a Democrat for all practical purposes. He caucuses with Democrats and his voter base is Democrats. The Republicans have not been absurdly successful in an democratic support sense. over the past 25 yesrs, they've steadily increase their reliance on electoral college bias, voter suppression, and a Republican judiciary. When the party's success depends on Supreme Court decisions made by a previous President they helped get installed by the Supreme Court overruling the voters, they are on very thin ice democratically. Republicans haven't won the popular vote for a non-incumbent since 1988, or 1980 if you consider VP GHW Bush as an incumbent.