When looking at the General Social Survey one of the most striking things is how much more the more educated and intelligent are in terms of accepting unpopular views. Since 2008 and the SPKMSLM variable has asked about anti-American hatred preached by Muslim clerics in the United States:
… consider a Muslim clergyman who preaches hatred of the United States.
If such a person wanted to make a speech in your community preaching hatred of the United States, should he be allowed to speak, or not?
The ideological breakdown is what you’d expect it to be, and tolerance for this sort of speech is low, at about 40% of Americans.
In case you are wondering, the impact of intelligence still matters after you correct for education. I ran a quick & dirty logistic regression, and you can see that below (in case you care, being a woman is associated with less tolerance for free speech here, and political ideology doesn’t matter much once you take into account religiosity):