The text outlines three of the major frames of reference through which Americans form their political opinions. Party identification is the first, referring to a person's ingrained sense of loyalty to a political party. It often remains stable through adulthood, but can be influenced or changed by the issues or candidates of the moment. Political ideology is another major frame of reference, and refers to an individual's coherent set of political beliefs (if they have them). In the United States, this can be broadly broken down into groups such as economic or social liberals or conservatives, libertarians, or populists. A third broad frame of reference is group thinking, in which individuals see politics through the lens of a group affinity. There are many different kinds of groups, including those defined by religion, economic class, region, race and ethnicity, gender, and age.