When any good people come to politics then he become bad its politics rule so before election everyone is good .
This is true for every career. As a student every one is idealist. But afterwards everyone and not just politician corrupt. As a doctor, you will cheat patients by unnecessary tests, prolong treatment, get commission from drug companies/ med rep for prescribing their products. As engineer, you will indulge in corruption, accept bribes from contractors and build shaky bridges. As school manager, you will organize mass copying on contract. In spite of all these malpractices, if you have some spare time, you will participate in anna rally and shout- Bharat mata Ki jai etc.