In this season of mass defections, all to the BJP, three interconnected political questions arise. Why do parties break up? Why do individuals defect? Do ideology, principle, even loyalty, matter?

All of these then lead to a central logical question: Why do some parties break up, or haemorrhage fatally, but some don’t?Let’s first check out the broad scoresheet over these months of high ‘mobility’. The destruction of Mamata Banerjee’s Trinamool Congress (TMC), or rather coup from within, has been the standout headline. But there’s competition. The rump of the Shiv Sena with Uddhav Thackeray is splitting again. In Jharkhand INDIA MLAs have cross-voted for NDA-backed independent Parimal Nathwani. Congress can draw some consolation from D.K. Shivakumar getting some from NDA to cross-vote in the MLC election in Karnataka.

Aam Aadmi Party had already lost seven, Biju Janata Dal has ‘contributed’ three to the BJP/NDA kitty, in not so recent a past Y.S. Jagan Mohan Reddy’s YSRCP (Yuvajana Sramika Rythu Congress Party) has shed members too, all adding to NDA (read BJP) numbers. The Shiromani Akali Dal, despite its religious glue and unique ideology has seen departures, including Manpreet Singh Badal. There’s also Manjinder Singh Sirsa, now a minister in Delhi.If I started listing the Congress people who walked across to the BJP, it would take up the entire length of this column. Let me, therefore, confine myself to those who’ve become chief ministers or central ministers with the BJP, or used to be chief ministers with the Congress. Chief minister, after all, is one of the highest positions a party can give.