nice find, check out this chart... the political statistician Nate Silver calls it the "Broadus Effect" http://3.bp.blogspot.com/_ov-pT1x-W8Y/TE4v1npkEJI/AAAAAAAADWM/phMnbnXYjaA/s400/broadus.png folks are more comfortable expressing their support with the automated polls rather than live human polls. See here for more of Silver's analysis: http://www.fivethirtyeight.com/2010/07/broadus-effect-social-desirability-bias.html