not often you can say this and mean it. a 2020 campaign trail surprise this week. bernie sanders has sold with a capital s. >> our jeanne moos has a look at the candidate dancing like nobody is watching. >> reporter: you know how bernie sanders could get a little grouchy? >> if we could keep that down a little bit. >> reporter: now you can't keep him down. this is the story of bernie's night as a not quite two months after his heart attack. ♪ >> reporter: the sound of the temptations moved him to the dance floor. and bernie invited woman after woman to take a spin. even if this one shyly resisted his attempt to twirl and even