I think he should tell the truth.
"Bush has bungled homeland security and the war on terrrorism to the point that the capture of UBL – although good news – means that the US has captured the figurehead of a terrorist movement that has spread throughout the world since 9-11.
"The Bush Administration may brag its success in capturing UBL. It is true, our fine military has struck an important blow against the headquarters of the most dangerous terrorist group that we know of. But the very same Bush Adminsitration admits that unknown numbers of Al Qaeda agents are inside the United States, actively plotting to conduct more attacks.
"In the last three years, this country has been through more orange alerts than babies have gone through Pampers. [Ok, might need to change that line] The Al Qaeda agents that have infilrated our country on George Bush’s watch will make sure that we continue to have more threats against airports, landmarks, and subways long after Osama has been put into his deep, dark hole.
"Why is that? It’s because Bush has underfunded homeland security and created a bureaucratic mess in the Department of Homeland Security, all while pursuing foreign adventures and alienating our allies. The Al Qaeda terrorists already in this country have been the greatest threat to national security since the war in Afghanistan sent UBL running from his sanctuary.
“George Bush won’t say this, but the chances of terror plots stopping after the capture of UBL are about the same as violence stopping in Iraq after Saddam was captured and his sons put on ice. Bush can’t be trusted with the security of this country, because he doesn’t know what the threats are, and he doesn’t know how to deal with them.”
Then add in some positive spin about what Kerry is going to do to bolster the FBI, increase port security, help first responders, etc. At least, that’s what I’d recommend to him.