In the nearly 60 year history of television this maybe the most demented interview ever. Rumor has it the Glover was high as a kite before going on the show. Watch how uncomfortable Letterman and Paul look while Glover goes off the wall. You can the impression that Letterman is scared.
Was it an act or just a promotion for the movie A River's Edge?
Letterman walked off the show after this interview. Was Glover really on acid?
http://www.youtube.com/watch?v=ALapHYNSmoA
Glover talks about it 20 years later.