Arvind Kejriwal is a rookie politician who defeated (three-time Chief Minister of Delhi) Sheila Dikshit in the Delhi Legislative Assembly elections (held today).
He co-founded a political organization named Aam Aadmi Party (Translation: Common Man's Party) that won 28 of Delhi's 70 seats in its electoral debut, just 3 shy of BJP (an established National Party), and more than three times the no. of seats won by Indian National Congress (the incumbent party in Delhi).
Relevant background information on Arvind Kejriwal [0]
[0] https://en.wikipedia.org/wiki/Arvind_Kejriwal
[Edit: corrected figures based on child comment]