When China invaded India, the communist party in India was calling nationwide protests "in support of china" and was running "fund raising drives". That was the first time Bal Thakare turned from a cartoonist to a mass leader.
The political party was truly formed when Islamists forced the central government to change Indian constitution to apply horrible Islamic Sharia law to ensure that a 60 year old lady divorced after 40 years of marriage will not get any alimony from her rich husband. Muslims across the mumbai would then celebrate their victory by blocking the traffic and holding Namaz on streets.
Bal Thakare seemed to be the only voice weaker sections of society had that time. Yes, like all other organizations even Shiv Sena was not perfect and many times local goons and mafias joined this party for their own gains but more or less this party remains much more faithful to common people than the other parties.
1. [http://en.wikipedia.org/wiki/Shah_Bano_case] 2. [http://en.wikipedia.org/wiki/Communist_Party_of_India#Commun...]
"a mob of some 2,000 Shiv Sena workers attacked and ransacked her uncle’s orthopaedic clinic"