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: Our momentum continues to build. I appreciate Jeff King's endorsement today! http://www.marksanford.com/2013/03/jeff-king-endorses-mark-sanford/  Responser: No Joel - SC voters liked Mr. Sanford and we love the fact he will represent us in DC! YOU GO MARK SANFORD!!
