convince others to agree with them, and then hope to see their policies enacted. They do their work in a
less well-defined realm of political discourse. These two missions are distinct, but the lines between the
groups pursuing them are not bright. We need concrete definitions to separate them.
I define a political party as an organized effort to gain political power (Schattschneider 1942; see
also Cohen et. al. 2001, forthcoming). Parties form a united front, putting aside their differences so that
they can capture control of government. They then use government to gain power and influence policy.
Those who form the united front often differ from one another in important ways. All they need have in
common is a desire to control government. They might include activists who have strong ideologies. Or
they might be a collection of unrelated interest groups. Parties can even be based entirely on patronage.
Some kinds of groups may be easier to unite or manage than others, but parties can be formed in many
ways. However the group is formed, the party binds its members’ efforts together in the service of their
collective goals.
I define ideology as a shared set of policy preferences. Like a party, an ideology unites many
different people, but unlike partisans, ideologues are united, but not a front. They really want the same
things. Members of parties expect to agree on little and to be indifferent on a lot of things; members of
ideology expect to agree on everything and to be indifferent about little. The shared set of preferences
may be logically coherent and derived from first principles, but it need not be. Ideologies are
comprehensive: They prescribe policy positions on nearly every issue on which there is any political
disagreement, and certainly across all domains of issues. This definition of ideology is consistent with
Converse’s (1964) notion of ideology as a system constrained beliefs, and is flexible in regards to the
origins of that constraint (see Noel 2005). To be politically relevant, an ideology must be shared by a
number of politically relevant people. Otherwise, it is just one person’s belief system. Ideologues want to
see their ideology implemented as policy and this requires many adherents.
3
This approach to ideology differs from that found in, for example, Gerring 1998, in which ideologies are
something that a party might have, and there is thus little need to distinguish them. I focus instead on the extent to
which an ideology exists without a party, thus asking where the ideology that a party adopts came from.
4
Convention