Chomsky is a tenured professor in the Ivory Tower -- how on -earth- does he classify as a dissident? If anything, Chomsky represents the dominant ideology in academia in America. Maybe he was a dissident sixty years ago, when he was relevant?
And as with all of these things they ebb and flow. I would challenge you on the point that he represents a dominant ideology any longer, he may have once and he may still have adherents but he is not as instrumental as he once was. So perhaps he started a dissident and will end as one too, but for different reasons.
A good hint your ideology is not “dominant” is you spend a great deal of time decrying what the government does and it carries on while ignoring or ridiculing your criticisms. For that matter, how can he both represent a dominant strain of thought and also be irrelevant?
Because this “strain of thought” only disagrees with the government on non-issues. They align pretty well on the questions of property, rights, freedom, etc.
Perhaps people living in countries who have been the subject of U.S. interventions might not see them as nonissues.