A TON of evidence.
We have not yet found stocks of weapons, but we are not yet at the point where we can say definitively either that such weapon stocks do not exist or that they existed before the war and our only task is to find where they have gone.
No stocks, no evidence. We're not talking about 'programs'. That line just doesn't fly. Either WMDs existed or they didn't. And perhaps if you'd quit listening to what the RNC and President wants you to use as talking points, you'd see the evidence just isn't what it was promised to be