They stoke communal sentiments, pit Hindus vs Muslims, make it seem like the minorities are out to destroy the Hindus, and a vast majority of the population just laps it up.
They have a giant misinformation network, which has recruited everybody from bots to popular actors to popular sportspeople and they spread out misinformation in a highly organized manner. Very effective at spreading FUD which translates into votes come election time.
Even now, on Twitter and Reddit you'll find thousands of posts about how the protesting farmers are khalistani terrorists.
Goebbels would be proud of what the BJP have accomplished.