Political science is the study of politics. It involves the study of structure and process in government - or any equivalent system that assures safety, fairness, and closure across a broad range of risks and access to a broad range of commons for its human charges. Accordingly, political scientists often study trade unions, corporations, churches or other forms of collective intelligence that are not "political" in the sense of influencing law or executive decisions - but have structure and process approaching that of government in complexity and interconnection.
Political scientists study the allocation and transfer of power in decision making. Because of the complex interaction of often conflicting interests, political science is often an applied instance of game theory.
Political processes are often associated with the possibility or the prevention of violence.
Since the end of the World War II, the study of International Relations, that is also part of Law, Economy, Sociology, among others, became an important area of Political Science. As the time passes, International Relations studies get more and more independent of Political Science, including the methodology and scholars themselves.
One thing that complicates the study of political science is that political scientists are themselves part of the political process, since their teachings provide the frameworks within which other commentators, such as journalists, pressure-groups, politicians and the electorate select what they see as the most viable options.
The complex interplay of economic and political choices is reflected in the field of political economy, where economics and political science overlap.
In the United States, political scientists look at a variety of data including elections, public opinion (on matters ranging from Social Security reform to foreign policy), institutional roles (how the U.S. Congress acts, where congressional power gravitates, how and when the Supreme Court acts, or does not act, etc.).
While historians look backward, seeking to explain the past, political scientists try to illuminate the politics of the present and predict those of the future.
See also: list of literature on political science