That's a strikingly high number. Do 2/3 of Americans even approve of GMO food?
Because few Americans have seen Measles, Mumps and Rubella first hand they are more willing to take irresponsible risks. Things like a 10% mortality rate make a disease feel safe because people think they will always be in the 90%. Anybody with a cursory knowledge of mortality rates knows that 10% is a horrifying number and that disease must be awful, some strains of Ebola kill 10% of people getting it.