Why Aren't There More (")Liberals(") In America?

E.g.

Not entirely clear what the question is, but it may very well be, at least in part: why don't more people describe themselves as liberals?

Hypothesis: because Reagan and the neo-Reaganites made 'liberal' a dirty word. Add to that that lots of liberals fled the fight and decided to start calling themselves "progressives" instead. That'll work until the next Reagan comes along and makes 'progressive' a dirty word.