Is Budget Planning Sequence Fatally Defective?

It used to be that the budget planning sequence went from proposal to estimate to soundbite. Today, however, we have a new game in town. Now we get estimates of the cost of a proposal before the proposal itself has even been designed. And the estimates themselves are made primarily to fit into a soundbite or two, usually about the direction of the budget. While this type of approach might result in decent budget policy, it is almost impossible to believe that good tax or expenditure policy will be a consequence.