The next few months are going to be dominated by the budget showdown between the two parties. It's helpful to step back from the specifics for a moment and consider the broader point, which is that the entire framework of this debate is being driven by the Republicans' desire to consider spending as an abstract proposition and Democrats' desire to consider it in the specific. Almost everything both parties will do revolves around that.

One of the most timeless and fundamental facts of American politics is that people oppose government in the abstract but favor it in the particulars. Republicans need to tailor their opposition to government to accommodate this reality. The largest programs -- defense, Social Security, Medicare, and Medicaid -- all command strong public support. (People show some willingness to cut defense, but many Republicans oppose any cuts in this category, so the party tends to shy away.) But Republicans have to cut something, and so, by process of elimination, they're left with cutting everything else.

Everything else falls into a catch-all known as "domestic discretionary spending," which accounts for every dollar of spending that isn't defense, entitlements, or paying interest on the national debt. This category accounts for less than a fifth of the federal budget, and it's been getting squeezed fairly hard for more than two decades. The budget debate we're having centers almost entirely on this one small slice of the budget. Why is that? Well, it's because it's a category of programs rather than a program itself. Cutting domestic discretionary spending is the closest Republicans can come to cutting spending in the abstract.

Of course, cutting domestic discretionary spending is not the same thing as cutting spending in the abstract. You have to cut individual programs. And that's where the Obama administration thinks it can turn the debate to its advantage. Turn to specifics, and Democrats can force Republicans to answer questions like, Does cutting spending on education or scientific research really help the next generation? (Obvious answer: no.)

This is driving the maneuvering on both sides. The administration thinks that if it offers up cuts, including cuts in programs it supports, it can get past the cut/not cut debate to a debate about specifics, which it can win. Thus you'll see spin like this:

"The debate in Washington is not whether to cut or to spend. We both agree we should cut," said a senior administration official, who briefed reporters Sunday night on the condition of anonymity because the budget had not been released. "The question is how we cut and what we cut."

Republicans want to keep the debate as abstract as possible, focusing on the general need to cut without focusing any attention on the programs themselves. Thus you see spin like this:

"The President talks like someone who recognizes that spending is out of control, but so far it hasn't been matched with action. And his only solution to one of the most significant problems facing our country is to lock in spending at levels we all know are completely unsustainable," Senate Minority Leader Mitch McConnell (Ky.) said in a statement. "Americans don't want a spending freeze at unsustainable levels. They want cuts, dramatic cuts."

In 1996, Bill Clinton won the budget showdown largely by turning the debate onto the specific programs Democrats called "M2E2": Medicare, Medicaid, Education, and the Environment. Republicans aren't touching Medicare and Medicaid -- indeed, defending every dollar of Medicare spending, wasteful or not, was the party's most popular tactic in the health care debate -- but they are slashing spending on public investment. Democrats are now focusing on what E.J. Dionne calls E2I2 -- education, energy, infrastructure and innovation.

But the larger picture is this: the budget debate we're having has virtually nothing to do with the budget deficit, and only a little to do with the size of government. It's a debate about a small slice of the federal budget, and it's happening because Republicans want to cut the size of government without coming out against actual government programs.