Essentially nowhere. John F. Cogan and John B. Taylor explain the details in a rather long but extremely readable analysis over at Commentary. I’ll send interested readers over there to read the whole thing, since excerpting it would not do it justice.
Put simply, the stimulus plans never had any chance of actually working. They were failures before they were enacted. The architects of the plans ignored some very substantial economic analysis and went with pure Keynesian approaches.
And wasted more than a trillion dollars of borrowed money in the process.
The authors are both professors at Stanford University and both fellows of the Hoover Institution. These are no lightweights. Go read their analysis of the enormous policy failures.