Has United States Become an Oligarchy?

According to Washington Times coverage of the research study in the link below, “America is no longer a democracy — never mind the democratic republic envisioned by Founding Fathers. Rather, it has… become a country led by a small dominant class comprised of powerful members who exert total control over the general population.”

That’s the definition of an oligarchy. And that’s the Hijacking of Social Responsibility, the Hijacking of the American Dream and the Hijacking of Governance.

Here’s the research citation:

Testing Theories of American Politics: Elites, Interest Groups, and Average Citizens
Martin Gilens and Benjamin I. Page (2014).
Perspectives on Politics, Volume 12, Issue03, September 2014, pp 564-581
Do you agree or disagree? Why?