I think the definition of what it means to reject a budget is very important here, as well as a better understanding of the government’s budget process.
The budget proposal that comes from the President includes many, many things:
- Aggregate spending levels across government.
- Detailed proposals on what agencies operating costs are, including things like how many F-35 fighters the Navy wants to buy.
- Estimates of revenues based on tax policy and economic conditions.
- Estimates of the cost of mandatory programs based on economic conditions, the number of beneficiaries, value of the benefits, etc.
- Proposals to change policies or priorities to reflect what the President wants to accomplish in the next year.
- Various other stuff, like estimates of the debt and deficit under future years according to the proposals in the budget.
So the Budget Committees of Congress are basically entirely focused on 1, 3, 4, and 6. Individual appropriations, authorization, and tax bills relate to 2, 3, 4, and 5.
What Republicans in Congress have said is that what they expected Obama to propose, mostly for #5, but also sort of for #1, was so truly awful that they didn’t even need to see the budget before declaring those proposals completely dead.
However, in order to have the budget process work, there’s really no way of getting around the need for the President’s budget to provide data for #2, 3, 4, and 6. Sure, Congress may make plenty of changes to those things, but Congress simply isn’t capable of doing its own ground-up estimate of how much printing materials are needed in the Department of Interior’s Office of the Inspector General; or how much the cost changes of thousands of pharmaceuticals used by the VA medical system will impact the budget. It’s impossible.
I’m not sure there’s precedent for a budget to be rhetorically rejected before it arrives in Congress, but the vast, vast majority of the data transmitted in the President’s budget will absolutely be used in the congressional budget process.
ETA: It’s also become common during floor debates on the budget for the party in opposition to the President to offer up “the President’s budget proposal” for a vote. It’s always voted down… and the fact that sometimes little changes to the budget make their way in to the amendment to make the “President’s budget” a little less attractive, well, surely that has nothing to do with the vote… right?