The politics of Spain takes place under the framework established by the Constitution of 1978. Spain is established as a social and democratic sovereign country wherein the national sovereignty is vested in the people, from which the powers of the state emanate. The form of government in Spain is a parliamentary monarchy, that is, a social representative democratic constitutional monarchy in which the monarch is the head of state, while the prime minister—whose official title is "President of the Government"—is the head of government. Executive power is exercised by the Government, which is integrated by the prime minister, the deputy prime ministers and other ministers, which collectively form the Cabinet, or Council of Ministers. Legislative power is vested in the Cortes Generales (General Courts), a bicameral parliament constituted by the Congress of Deputies and the Senate. The judiciary is independent of the executive and the legislature, administering justice on behalf of the King by judges and magistrates. The Supreme Court of Spain is the highest court in the nation, with jurisdiction in all Spanish territories, superior to all in all affairs except constitutional matters, which are the jurisdiction of a separate court, the Constitutional Court. Spain's political system is a multi-party system, but since the 1990s two parties have been predominant in politics, the Spanish Socialist Workers' Party (PSOE) and the People's Party (PP). Regional parties, mainly the Basque Nationalist Party (EAJ-PNV), from the Basque Country, and Convergence and Union (CiU) and the Republican Left of Catalonia (ERC), from Catalonia, have also played key roles in Spanish politics. Members of the Congress of Deputies are selected through proportional representation, and the government is formed by the party or coalition that has the confidence of the Congress, usually the party with the largest number of seats. Since the Spanish transition to democracy, when parties failed to obtain absolute majorities, the tendency was to form minority governments. However, this tendency was broken in 2020 with the formation of the Second government of Pedro Sánchez, formed by members of the Spanish Socialist Workers' Party and Unidas Podemos, as well as independents proposed by both parties. This was the first nationwide coalition government to be formed in Spain since the Second Spanish Republic. Regional government functions under a system known as the state of autonomies, a highly decentralized system of administration (systematically ranked 2nd in the world after Germany at the Regional Authority Index,