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: Bruce Braley thinks #Obamacare is "doing a lot of great things in Iowa" and likens the President and Secretary Sebelius to the Wizard of Oz. Remember in the end when we realize the Wizard of Oz is a man who cannot actually do the things he claims he can do?  Responser: We need Toto to pull back the curtain. Who's back there anyhow?
