The more the public learns about the health care bills under consideration before Congress, the less they are liked. A majority of Americans now say that government has no business attempting to provide health care for America. Additionally, by switching the debate to the 9/11 terrorists, it becomes an indictment of the Bush Administrations use of vigorous interrogation techniques on the terrorists themselves. This will provide yet another venue for America to "look bad" before the world and show just how wonderful "The One" is...yeah right.
A civil trial in which the rules of evidence demand that the prosecution provide the defense with all the information that it has acquired through the course of it's investigation. In this instance, the prosecution will have to provide the defense with a myriad of secret information on how the US has been able to either infiltrate Al Queda or how our government has been able to kill the leadership of that terror organization.
This will in effect, make America far less safe and much more open to further attacks...which may very well be what the Obama Administration has decided. After all, the NY Times (a primary supporter of Mr. Obama) has often published secret information on US intelligence gathering techniques...with the net result that we have been less and less able to hunt down those members of Al Queda.
UPDATE: From James Taranto of the WSJ:
You have to wonder if the Obama administration and its supporters bothered to think through the implications of their decision to try Khalid Sheikh Mohammed and four other enemy combatants as civilians. An immediate effect, and one that will only be strengthened by an actual trial or trials, is to bring 9/11 back into the public consciousness. That can't be good for President Obama...Yet the political pressure for a conviction will be immense. "Anything short of slamdunk convictions will empower the president's critics," opines Devlin Barrett of the Associated Press. Not only that, but an acquittal would put the administration in the position of having either to free a dangerous terrorist or to hold indefinitely someone who has been acquitted--either way, a disastrous failure for the administration's antiterror policies. The judiciary will not be immune to these pressures. No trial judge will want to be known as the Lance Ito of 9/11. More importantly, appeals judges--including Supreme Court justices--will surely hesitate to let KSM off on a technicality. But one man's technicality is another's violation of due process; and the corollary of treating KSM like ordinary criminals is treating ordinary criminals like KSM.