In other words, most of the really bloody fights will come later. Even so, there will be enough meat on these bones to start a brawl or two. Case in point: Trump’s proposed cuts to the State Department have moved Republican Senator Lindsey Graham to declare the package “dead on arrival.” So that debate promises to be lively.

More broadly, the basic structure of the blueprint—in which Trump wants to add $54 billion in defense spending by whacking an equivalent amount from non-defense programs—would blow up the 2011 sequestration agreement (which split cuts evenly between defense and non-defense programs) and thus require a change in the law in order to even be considered. But we’ll get to all that fun in a minute.

The practice of submitting a skinny budget is relatively new. The Budget and Accounting Act of 1921 requires the president to send Congress a spending plan early in each new session. The exact deadline has been tinkered with over the decades. Until 1990, however, it fell so early in January that, during presidential transitions, the decamping president was obligated to submit a budget on his way out the door, which could then be revised by his successor. (So it was that Ronald Reagan filed the underlying budget for George H.W.’s first year in office, as Carter had for Reagan, Ford had for Carter, and so on.) Under Bush 41, the official deadline was loosened just enough––from early January to early February––to enable the outgoing president to leave this duty to the incoming one, which promptly became the standard.

Practically speaking, of course, it would be madness for a fledgling White House to try to hammer out a full budget in its first couple of weeks. Thus was born the skinny budget. During their first February in office, Clinton, Bush 43, and Obama each provided a budget overview to Congress in conjunction with their first joint address to lawmakers. Such overviews typically run in the digestible 100-200- page range, rather than the doorstop-sized full budgets submitted in the spring.

(Some of the astute among you will notice that Trump has missed the early February deadline even with his skinny budget—as did those before him. As is so often the case in Washington, deadlines are forever being pushed and tweaked and ignored to the point where one might wonder why Congress bothers to keep them on the books. But that is a topic for another day.)

Already, the skinny budget is making the rounds in the executive branch. On Monday the White House sent the numbers out to federal agencies and departments in a process known as “passback.” Along with the topline amounts they are being allotted, agencies received suggestions from Mulvaney’s Office of Management and Budget on how to hit those numbers. After spending a few days reviewing the proposal, agency officials will come back to OMB with their thoughts on where the cuts—or, in the case of the Pentagon, the additional billions—should be directed. Serious appeals go up the food chain to Mulvaney or even the White House.