From The Art and Popular Culture Encyclopedia
A political organization is any organization that involves itself in the political process, including political parties, non-governmental organizations, advocacy groups and special interest groups. Political organizations are those engaged in political activities (e.g., lobbying, community organizing, campaign advertising, etc.) aimed at achieving clearly-defined political goals, which typically benefit the interests of their members.
While parties are one type of political organization that may engage in some or all of those activities, they are distinct in that they typically focus on supporting candidates for public office, winning elections and controlling government.