Politics in West Bengal is dominated by the following major political parties, the Communist Party of India (Marxist), the Indian National Congress (also known as Congress(I)) and the Trinamool Congress. All three are leading a regional bloc of parties, the CPI(M) heads the Left Front and the Trinamool Congress has emerged as the main component of the National Democratic Alliance in the state. The Congress(I) generally head informal alliances of various minor parties that align ahead of elections.

In 1977 the Left Front won the state assembly elections, and since then the state is ruled by communists and other left groups. The West Bengal state government hold the Indian record of period of governance. The last election won by the Left Front was the 2006 state assembly election.

Until 2001, Jyoti Basu was the Chief Minister of the state. After his resignation, due to health reasons, Buddhadev Bhattacharya became the Chief Minister of West Bengal.

In the run up to the 2011 elections, the state has witnessed several violent clashes between the workers of the opposition parties and the ruling party cadres.

West Bengal /bɛŋˈɡɔːl/ (proposed new English name: Paschim Banga) is a state in the eastern region of India and is the nation's fourth-most populous. It is also the seventh-most populous sub-national entity in the world, with over 91 million inhabitants. Covering a total area of 34,267 sq mi (88,750 km²), it is bordered by the countries of Nepal, Bhutan, and Bangladesh, and the Indian states of Orissa, Jharkhand, Bihar, Sikkim, and Assam. The state capital is Kolkata (formerly Calcutta). West Bengal encompasses two broad natural regions: the Gangetic Plain in the south and the sub-Himalayan and Himalayan area in the north.

In the 3rd century BC, the broader region of Bengal was conquered by the emperor Ashoka. In the 4th century AD, it was absorbed into the Gupta Empire. From the 13th century onward, the region was ruled by several sultans, powerful Hindu states and Baro-Bhuyan landlords, until the beginning of British rule in the 18th century. The British East India Company cemented their hold on the region following the Battle of Plassey in 1757, and the city of Calcutta (now known as Kolkata) served for many years as the capital of British India. The early and prolonged exposure to British administration resulted in expansion of Western education, culminating in development in science, institutional education, and social reforms of the region, including what became known as the Bengal Renaissance. A hotbed of the Indian independence movement through the early 20th century, Bengal was divided in 1947 along religious lines into two separate entities: West Bengal – a state of India – and East Bengal, which initially joined the new nation of Pakistan, before becoming part of modern-day Bangladesh in 1971.

The United States is a federal constitutional republic, in which the President of the United States (the head of state and head of government), Congress, and judiciary share powers reserved to the national government, and the federal government shares sovereignty with the state governments.

The executive branch is headed by the President and is independent of the legislature. Legislative power is vested in the two chambers of Congress, the Senate and the House of Representatives. The judicial branch (or judiciary), composed of the Supreme Court and lower federal courts, exercises judicial power (or judiciary). The judiciary's function is to interpret the United States Constitution and federal laws and regulations. This includes resolving disputes between the executive and legislative branches. The federal government's layout is explained in the Constitution. Two political parties, the Democratic Party and the Republican Party, have dominated American politics since the American Civil War, although other parties have also existed.

Narendra Damodardas Modi (Gujarati: નરેન્દ્ર મોદી; born 17 September 1950) is the current Chief Minister of the Indian state of Gujarat. Born in a middle class family in Vadnagar, he was the third of six children born to Damodardas Mulchand Modi and his wife Heeraben. He has been a member of the Rashtriya Swayamsevak Sangh (RSS) since childhood also having interest in politics since adolescence. He holds a master's degree in political science. In 1998, he was chosen by L. K. Advani, the leader of the Bharatiya Janata Party (BJP), to direct the election campaign in Gujarat as well as Himachal Pradesh.

He became Chief Minister of Gujarat in October 2001, promoted to the office at a time when his predecessor Keshubhai Patel had resigned, following the defeat of BJP in the by-elections. His tenure as chief minister of Gujarat began on 7 October 2001, and he is the longest serving Chief Minister of the state of Gujarat. In July 2007 he became the longest serving Chief Minister in Gujarat's history when he had been in power for 2063 days continuously. He was elected again for a third term on 23 December 2007 in the state elections, which he had cast as a "referendum on his rule".

Mamata Banerjee (Bengali: মমতা বন্দ্যোপাধ্যায়, pronounced [mɔːmoːt̪ʰaː bɛːnaːrjiː]; born 5 January 1955) is the 11th and current Chief Minister of West Bengal. She is the first woman to hold the office. Banerjee founded All India Trinamool Congress in 1997 and became chairperson, after separating from the Indian National Congress. She is usually called "Didi" (meaning elder sister). She is often cited by the media and critics to be as "megalomaniac, eccentric and populist politician".

Banerjee pulled off a landslide victory for the All India Trinamul Congress (AITMC ) or (TMC) in West Bengal by defeating the world's longest-serving democratically-elected communist government, the Communist Party of India (Marxist)-led Left Front government, bringing to an end 34 years of Left Front rule in the state. Banerjee previously served as a Minister of Railways twice, Minister of Coal, and Minister of State for Human Resource Development, Department of Youth Affairs and Sports and Women and Child Development in the cabinet of the Indian government. She opposed forceful land acquisition for industrialisation by the then communist government in West Bengal for Special Economic Zones at the cost of agriculturalists and farmers.