Cashing in the four weeks of vacation - and two years of savings - Rajveer Singh Mann caught a flight from California to his hometown of Ludhiana and got straight to work. Normally, the 32-year-old's day job is working with a bio-tech firm. But his sabbatical finds him going door-to-door with NRIs like himself to build support for the Aam Aadmi Party or AAP in Punjab, which votes in less than a month.