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: We are still working hard to make sure that student loan interest rates don't double for our local students. Making college affordable is critical for middle class families.  Responser: Exactly what is a middle class family?
