Considering political machines, which are effectively coalitions or parties organizing, collaborating, and competing for political power, this fifteenth chapter looks past the ages of revolution and constitution formation wherein political ideologies were first represented in political processes; it considers how political ideology figures into established political landscapes as parties matured and competed for power. More than any other, this chapter distinguishes between ideology as a feature of mind, and political parties as vehicles for gaining and maintaining power. Hearkening back to Hume’s distinction between principles, genuine ideological commitments extending from individual temperamental differences, and interests, practical desire for power and resources extending from material desire, we can see that political machines are creatures of interest. What political machines do with principled ideological commitments depends on how they advance or detract from practical interest in obtaining power and resources. As discussed, political machines alternately stoke and suppress ideological principles as they grant or thwart political interests. As the size, power, and organization of party machines grew over time, machines became powerful groups within the national whole; and with their growth, party machines gained the power to redirect or suppress ideological divisions within the body politic.