Ideological reasoning (or top-down thinking) refers to the thought process which begins with generalizations and moves to more specific ideas. An individual's ideological reasoning is rooted in his or her core values, morals, personal principles, and personal perception.
For example, examine the beliefs behind a typical Democrat or Republican. Each individual's life is based upon his or her own morals, beliefs, and values. Therefore, a person who thinks similar to a Democrat will join the Democratic party. This said, he or she will disagree vehemently with the ideas of a Republican. Given that the individual's reasoning falls more with the Democrats, he or she will specify his or her alignment with a Democratic state of mind. Validation of being a Democrat comes from the likeness of the group's thoughts to that of the individual.