Definition: Given a 'poster' sentence and a corresponding 'response' (often, from Facebook or Reddit)classify the sentiment of the given response into four categories: 1) Positive, 2) Negative, 3) Neutral, and 4) Mixed if it contains both positive and negative.
Input: Poster: Fifty years ago, men and women of every race, creed and religion gathered on our National Mall to declare that the scourge of discrimination could not overpower a nation dedicated to equality and freedom.  Responser: Then along came LBJ's war on poverty and everything turned to crap.
