The five major functions of a political party are recruitment of candidates, fundraising, campaign support, advocacy of political issues and government organization. The Democrats and Republicans are the dominant political parties in the United States.
The primary function of a political party is the recruitment of qualified candidates to run for public office. In order to shape policy, parties need officeholders at the local, state and national levels. Parties seek out candidates with ties to the community and a deep understanding of the issues and concerns of the constituency. The candidate's ability to raise money is also critical, as fundraising is among the most time-consuming and important functions of the party. Political parties also provide a range of support services for candidates during their campaigns, including polling, opposition research, voter lists, position papers, strategic and legal counsel, and media buying. Voters look to political parties to define the issues of the day and advocate for positions consistent with their core values.
In the United States, government organization is primarily a function of political parties at the national level, where they handle responsibilities within each of the three branches of government. In the legislative branch, party members select the leadership, introduce legislation and confirm executive and legislative branch appointments. In the executive branch, the party in power is responsible for thousands of appointments to various positions.