"Off a cliff"...?

Chris Matthews on Michele Bachmann.
Speaking of ledership, I don't know where the words "Off a cliff" [*] came from but maybe the push that Matthews is implying, and which I might turn on him. Not to mention a "slippery slope" metaphor of rhetoric. Is it a mix of exaggeration and inaccuracy? Or just speaking in tongue, or the language that some might hear better?
But maybe we could see "balloon head" as a "Sputnik moment" ?

[*] I really thought I heard it prior to post, but maybe it was more mis-hearing

[Speaking of Neitzche: or Lex Lootor]