Because he had 30 seconds to talk to the American people about issues of substance, and the American Peoplw did not want to see two grown men in a spat about who saw whop at the national prayer breakfast.
And Cheney's comeback would have bneen "oh, you're right, I did see you.... once. Short career, huh Senator?"
The fact that the phrase "Office of Special Plans" was never mentioned during that debate, in and of itself, is just criminal. That whole debate--and, true, that whole race--should have been shooting fish in a barrel. At BushCo's peak Cheney's approvals were never that high. And Iraq was Cheney's baby and everyone knew it. Even though it took Kerry until September to figure out he might want to criticize the war, the VP debate absolutely should have been a slam dunk. We've never had a VP who ran things befre, and we're just talking aout it now? Just say Doug Feith. 90+% of viewers would have no idea who he was, and would have been very interested to learn that he was in fact ths stupidest guy on the face of the planet. All this is to say nothing of the fact that the words Abu Ghraib never passed his or Kerry's lips.
I was an Edwards supporter in the 04 primaries, and all told, he's still probably my second option today, assuming Gore doesn't get in and Clark doesn't get a foothold. But the burden of proof is on him after his chokejob in 04, and I've got to hear something better than "the consultants ate my homework." That was Gore's excuse in 02, and 04 was a very different race in which even the lowest of low-info voters knew there were stakes; there was none of the 00 "who cares, what's the difference" Naderite, RATM cynicism to fight on our side. It's pretty close to inexcusable.
