Adding weight to the notion “money is power,” a new study demonstrates that rich and powerful special interests have the biggest influence in U.S. politics. The implication? The nation is ruled by an oligarchy, not a democracy. The Northwestern and Princeton University study compared 1,800 policies enacted from 1981 to 2002 to the expressed preferences of average Americans, wealthy Americans and large special-interest groups. Based on political results, they determined that the economic elite wielded the most clout. “Mass-based interest groups and average citizens have little or no independent influence,” the study concluded.