Direct election is a system of choosing political officeholders in which the voters directly cast ballots for the persons or political party that they desire to see elected. The method by which the winner or winners of a direct election are chosen depends upon the electoral system used. The most commonly used systems are the plurality system and the two-round system for single-winner elections, such as a presidential election, and party-list proportional representation for the election of a legislature. By contrast, in an indirect election, the voters elect a body which in turn elects the officeholder in question. In a double direct election, the elected representative serves on two councils, typically a lower-tier municipality and an upper-tier regional district or municipality. The European Parliament has been directly elected every five years since 1979. Member states determine how to elect their representatives, but, among other requirements, they must be directly elected. The United States House of Representatives has been directly elected using first-past-the-post voting since its inception in 1789. The United States Senate begin directly electing senators in 1914—after the passage and ratification of the Seventeenth Amendment to the United States Constitution. The president of France has been directly elected with the two-round system since the 1962 French presidential election referendum. The president of the Philippines is elected by national popular vote in elections. The idea that heads of state be elected directly by the people progressed slowly throughout the eighteenth and nineteenth centuries. This differs from parliamentary systems where executives derive power from the legislative body. Many African nations have moved from parliamentary to presidential systems. Regardless of constitutional structures, presidents often have immense power over other political decision-making bodies. Given this power, much of the political violence around elections stems from the elections of presidents.