Justice Markandey Katju writes: Politicians from India’s opposition parties have been signing up for a BJP membership in droves of late (the latest is Sanjay Nirupam of Congress). This has accelerated after the arrests of Delhi Chief Minister Arvind Kejriwal and other Aam Party leaders, and former Jharkhand Chief Minister Hemant Soren. These cut across party lines and states, and almost all got a reprieve on entering the BJP ‘washing machine’ and became as pure as the driven snow.