It's pretty telling that even an article trying to question the culture of unquestionable-exceptionalism is still chock-full of jingoistic language that says "if we just fix a few things we'll be the best country on earth again", as if such a thing was or is factual or even possible.
Not "exceptionalism is a myth" but "exceptionalism needs a new paint job". This is what passes for dissent in mainstream American discourse.