The following quote is from Dr. Jon Wisman, American University, and Dr. Aaron Pacitti, Siena College, (Exploding Inequality Is Threatening Our Democracy):
"Throughout history until quite recently, a small elite controlled governments to protect their wealth and insure that they could capture any income beyond what the rest of the population required for survival...The birth and expansion of democracy was vehemently opposed by the rich elites who had always held and benefited from their monopoly control of government...The extraordinary hardship of the Great Depression significantly delegitimized the rich's contention that unbridled free-market capitalism was in everyone's interest. The consequence was that, between the 1930s and 1970s, workers were able to use the right to vote to create government measures that would tame the excesses of free markets, reduce inequality, and significantly improve the lives of most Americans."
"If democracy is to endure, it's time for the non-elites to recognize that class warfare is being waged against them and rigorously fight back. It isn't just their material well-being that's at stake, it is also their freedom and our democracy."
(Also, see "Democracy and the Policy Preferences of Wealthy Americans" and "U.S. Policies Favor The Wealthy, Interest Groups, Study Shows")