Update: It looks like a hoax.
After rewatching the clip, Pennebaker told the Politico’s Ben Smith, “He does not say that. He does not say that … What he says is he’s surprised Perot’s numbers are holding. He says they must be shitting in the White House.” Pennebaker also told Smith that when the movie was released in theaters, no one thought Kantor said what he’s now alleged to have said, and that he thinks audio was dubbed onto the original video. Smith also spoke to the editor of the YouTube clip, and reports the editor “said that he enhanced, but didn’t alter, the audio in the second portion of the video.”
Ok, so I was duped. The disputed piece was taken off YouTube – you can see the full video here: