evidence suggests that over the last several decades, the strength of party identification has been weakening, so this may be a less important function for parties to provide than it was in the past. Structure of political parties Political parties are often structured in similar ways across countries. They typically feature a single party leader, a group of party executives, and a community of party members. Parties in democracies usually select their party leadership in ways that are more open and competitive than parties in autocracies, where the selection of a new party leader is likely to be tightly controlled. In countries with large sub-national regions, particularly federalist countries, there may be regional party leaders and regional party members in addition to the national membership and leadership. Party leaders Parties are typically led by a party leader, who serves as the main representative of the party and often has primary responsibility for overseeing the party's policies and strategies. The leader of the party that controls the government usually becomes the head of government, such as the president or prime minister, and the leaders of other parties explicitly compete to become the head of government. In both presidential democracies and parliamentary democracies, the members of a party frequently have substantial input into the selection of party leaders, for example by voting on party leadership at a party conference. Because the leader of a major party is a powerful and visible person, many party leaders are well-known career politicians. Party leaders can be sufficiently prominent that they affect voters' perceptions of the entire party, and some voters decide how to vote in elections partly based on how much they like the leaders of the different parties. The number of people involved in choosing party leaders varies widely across parties and across countries. On one extreme, party leaders might be selected from the entire electorate; on the opposite extreme, they might be selected by just one individual. Selection by a smaller group can be a feature of party leadership transitions in more autocratic countries, where the existence of political parties may be severely constrained to only one legal political party, or only one competitive party. Some of these parties, like the Chinese Communist Party, have rigid methods for selecting the next party leader, which involves selection by other party members. A small number of single-party states have hereditary succession, where party leadership is