content: The 10% number is bullshit, and Stossel should know better.  Ok, I did some digging, and found this study from 2015:  Google’s search algorithm can easily shift the voting preferences of undecided voters by 20 percent or more—up to 80 percent in some demographic groups—with virtually no one knowing they are being manipulated, according to experiments I conducted recently with Ronald E. Robertson . https://www.politico.com/magazine/story/2015/08/how-google-could-rig-the-2016-election-121548 We present evidence from five experiments in two countries suggesting the power and robustness of the search engine manipulation effect (SEME). Specifically, we show that (i) biased search rankings can shift the voting preferences of undecided voters by 20% or more, (ii) the shift can be much higher in some demographic groups, and (iii) such rankings can be masked so that people show no awareness of the manipulation. Knowing the proportion of undecided voters in a population who have Internet access, along with the proportion of those voters who can be influenced using SEME, allows one to calculate the win margin below which SEME might be able to determine an election outcome. https://www.pnas.org/content/112/33/E4512 As predicted, subjects spent far more time reading Web pages near the top of the list. But what surprised researchers was the difference those rankings made: Biased search results increased the number of undecided voters choosing the favored candidate by 48% compared with a control group that saw an equal mix of both candidates throughout the list. Very few subjects noticed they were being manipulated, but those who did were actually more likely to vote in line with the biased results. https://www.sciencemag.org/news/2015/08/internet-search-engines-may-be-influencing-elections  So the 10% number might be with undecided voters.