A celebrity?
I've seen him interviewed once on Charlie Rose.
In May 2002 CNN put him on with Bill Bennett.
In 1986 he debated Boston university president John Silber on local Boston TV.
How is he a celebrity?
He mentioned in a speech once how someone on NPR wanted to talk to him, and how the higher-ups at NPR canceled and then limited his appearance, as he was apparently banned.
He also was prevented by the IDF from attending a talk at Birzeit university in the West bank, something he said hadn't happened (being refused admittance to a country he was to give a unievrsity talk to) since he tried to enter Czechoslovakia in 1968.
Even The Nation has spiked positive reviews of his books.
Someone with so little exposure on US airwaves over the decades is not a celebrity.