While not agreeing to the parent comment, it comes from the domestic politics now playing out in that state. After India got independent in the 40s, communists were the main opposition political party in the country for decades. Now, their presence in power is mostly confined to just this small state. While the center and most states are ruled by a hindu nationalist party. This has led to the politics in kerala moving to a sort of secessionary path. A political alliance of the communist-christian-muslim groups against hindu groups and rest of india.