Easy. A LOT more people in the country disagree with the incoming president than not.  By enlarge key issues like RvW and climate change are supported by the vast majority of people.  Democrats are not done.  R's are old and white.  If trends continue you're the ones in trouble.  HRC won handily in the under 40 crowd.  
Trump barely won and has no mandate.  That's my point.  We'll see where this goes but I think trump looses interest in the job and its world wide demands in about 6 months.