
Pew Research Center
The Pew Research Center is an American "fact tank" based in Washington, D.C. that provides information and data on issues, attitudes and trends shaping the United States and the world. It was established in 2004 as a nonpartisan subsidiary of Pew Charitable Trusts.
The group's Journalism.org site focuses research on public opinion and issues within news media. It's research is often cited in media bias research done by AllSides, including the 2014 Where News Audiences Fit on the Political Spectrum study.
Sources: Pew Research and Wikipedia
Political polarization – the vast and growing gap between liberals and conservatives, Republicans and Democrats – is a defining feature of American politics today, and one the Pew Research Center has documented for many years.
Beginning with a survey of more than 10,000 adults conducted in early 2014, this Pew Research Center series further addresses the nature and scope of political polarization in the American public today, how it has changed over the decades, and how that interrelates with government and political engagement. Reports in the series explore in more detail the current political landscape, and the ways in which ideological divisions in the American public are reflected in people’s personal lives and how they consume news and information about politics.