20 MPs of Kerala are a insignificant number including ruling parties. It isn't worth messing with Tamil politicians...you know they are some of the richest,influential..even if they live inside tihar jail. The most common way these caste/ethnicity based leaders in tamilnadu do is to point towards a target..this time they want to target Kerala(dam issue) and their media, every state mechanism works collectively in concentrating on adamant decision of not allowing the dam to decommission.
They don't mind killing 40lakhs people in their neighbouring states unless Centre intervenes. That is the Mentality. Here political equation or Congress Bashing or BjP glorification don't help. the Politicians of Kerala are really concerned. they can't do anything except Centre acting to decommission Mullaperiyar Dam.