Abstract :
What is a party? This article presents the argument that the formal party apparatus is only one part of
an extended network of interest groups, media, other advocacy organizations and candidates. The
authors have measured a portion of this network in the United States systematically by tracking lists
of names transferred between political organizations. Two distinct and polarized networks are
revealed, which correspond to a more liberal Democratic group and a more conservative Republican
group. Formal party organizations, like the Democratic National Committee and the Republican
National Committee, tend to receive information within their respective networks, which suggests that
other groups serve to funnel information towards the formal party.
