The Pew Research Center published a 2014 study that dissects how Americans of varying political persuasions interact with each other and get informed about politics.
From Political Polarization & Media Habits 10/21/14
Mugar Reference X HN90 .P8G3 2010-2011+; 1935/71-2009 (in storage). also
The Gallup poll cumulative index : public opinion, 1935-1997 Mugar HN90 .P8G29 1999
Gallup Poll Briefing 01/15/2002+ through Business Source Complete