Sorry to puncture your zeal, but Mr. Chomsky is quite welcome in the US. You see, he is a citizen of the US, where he enjoys his right to free speech, which the majority of US citizens respect. We are not scared of opinions. Indeed, dissent is considered patriotic here.
Islamic State militants blow up ancient Arch of Triumph in Palmyra (Reuters)
from the article: Noam Chomsky denied entry into Israel and West Bank