Who is Annamalai, IPS officer-turned-politician at center of BJP-AIADMK fallout?

Bharatiya Janata Party (BJP)'s Tamil Nadu chief K Annamalai is at the center of the party's recent fallout with the All India Anna Dravida Munnetra Kazhagam (AIADMK). The rift stemmed from Annamalai's controversial claim that Dravidian stalwart CN Annadurai, Tamil Nadu's first chief minister, on whose principles the AIADMK was formed, had to apologize for insulting Hinduism. While the BJP has no significant ground in Tamil Nadu on its own, the BJP choosing Annamalai over the AIADMK has divided opinions.