Time to use Bush's "Bring it on" in a commercial

Now that a group is finally using "Mission Accomplished" in an ad, why hasn't Kerry, the DNC, or one of "our" PACs or 527s used Bush's message to the insurgents in Iraq -- "those who think they can kill Americans... bring it on... we're plenty tough enough..." -- on a TV spot.  This could be done as a split-screen (e.g.) with the other half showing numbers of American service men and women killed and injured.  This would devastatingly show the Chimp for the arrogant bastard that he is: someone literally happy to sacrifice others' lives  (goes to the character "issue").

So why hasn't anyone done it yet?  I would think such an ad should run right up to election day.  What am I missing?