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 first volunteers of 2012! Email volunteer@tammyduckworth.com if you want to be next!  Responser: Tammy, I would like to hear your position on NDAA...how would you have voted?
