May 12, 2016

Year Republicans Democrats Independents
2001 21% 43% 43%
 2003 22% 43% 40%
2004 17% 40% 37%
2005 19% 45% 46%
2006 17% 43% 44%
2007 18% 48% 40%
2008 19% 50% 44%
2009 19% 50% 39%
2010 24% 53% 46%
2011 27% 56% 51%
2012 25% 62% 52%
2013 29% 59% 57%
2014 30% 64% 58%
2015 32% 66% 61%
2016 33% 70% 61%

Pew Research Center