Over 80 percent of Americans support “mandatory labels on foods containing DNA” page 4 on http://agecon.okstate.edu/faculty/publications/4975.pdf

The washington Post writes about it too: http://www.washingtonpost.com/news/volokh-conspiracy/wp/2015/01/17/over-80-percent-of-americans-support-mandatory-labels-on-foods-containing-dna/