According to Americans, free speech in that country went from being a left-wing rallying cry in the 60’s (when leftism was countercultural, and students wanted to be able to organize politically on campus) to being a right-wing rallying cry today (when rightism is rather liberal, and people want to be able to violate speech norms about racism and equality).
In Europe, free speech has never really been a respectable rallying cry. What freedom of expression as an enlightenment value is to America, reason and tolerance are to Europe.