Assuming that income is an indicator of intelligence the answer is yes, Democrats are brighter than Republicans.

States ranked by median household income: https://en.wikipedia.org/wiki/List_of_U.S._states_by_income

States that vote Democrat: http://www.politifact.com/punditfact/statements/2013/nov/10/george-will/george-will-paints-dire-electoral-picture-gop-says/

http://www.politifact.com/truth-o-meter/statements/2014/jul/29/facebook-posts/are-97-nations-100-poorest-counties-red-states/