India has a federal parliamentary democratic republic system modeled after the UK. The Prime Minister is the head of government and the President is the head of state. Power is shared between the central government and state governments. National and regional political parties contest power. Major parties include the Indian National Congress and the Hindu nationalist BJP. Elections involve over 700 million voters and take place over multiple dates for logistical reasons. Caste and religion influence voting patterns, and issues in politics include charges of criminality against politicians and Maoist violence in certain states.