You don't understand. The Christians in India don't see foreign evangelicals as a bad thing, but as people doing holy work. So when you work against them, they see it as working against Church and general interests of Christians. ANd they don't care about the constitution or anything. They want full freedom to do what they want. At the same time they will deny anyone else such freedom to convert their own people. They are a very naive, confused, dissociated population of India. At the same time, subconscious extremists (they dont acknowledge them to be so even to themselves), and you will see that in how aggressively they fight back when their 'freedoms' are targeted.
Just clarifying one more thing- It is not like they (the non-evangelical christans who are just converts and don't do anything else) want to convert India to christian (they don't care and is not much religious really), but they see evangelicals as noble people doing gods work and will not allow anyone to target them, whether they agree with them or not.