Political parties in the United States are organized at the national, state, county, and precinct levels. They hold temporary conventions and primaries to select delegates and alternates to attend higher-level conventions. At state conventions, delegates select party leaders and draft platforms, and in presidential election years also select delegates for the national convention. The two major parties, Democrats and Republicans, have different processes for selecting national convention delegates, with Democrats using a hybrid primary-caucus system in Texas called the "Texas Two-Step."