Evidence of al Qaeda-Iraq link?

Could Stephen Hayes be correct about "Saddam's al Qaeda Connection"? Hayes writes in The Weekly Standard of the growing evidence of such a connection, which, if fully publicized, would silence the critics of the US President. Yet if this is so, then it is difficult to understand why he would keep quiet about so much of this information.

The Bush administration has thus far chosen to keep the results of its postwar findings to itself; much of the information presented here comes from public sources. The administration, spooked by the media feeding frenzy surrounding yellowcake from Niger, is exercising extreme caution in rolling out the growing evidence of collaboration between al Qaeda and Baathist Iraq. As the critics continue their assault on a prewar "pattern of deception," the administration remains silent.

Why? If such evidence actually exists, then revealing it would get Bush off the hook with his partisan critics, as well as rescue the political career of his friend Tony Blair. And, most significant of all, it would put the attack on Iraq in an entirely different light, especially in those countries that were most sceptical about it to begin with.