Earlier this week, President Trump issued a proposed government budget for FY2018 calling for the largest reduction in domestic program spending since the aftermath of World War II. The White House budget would increase spending on defense by 10%, offsetting that amount by a similar reduction in spending on domestic programs. Because current defense and domestic spending are roughly equal, the budget in effect calls for domestic agencies in the aggregate to reduce spending by the same 10%. (There would be no cuts in entitlement programs such as Social Security and Medicare.)

Certain agencies – Homeland Security and Veterans Affairs - are exempt from cuts. The proposed cuts would fall unevenly on the remaining agencies, with EPA (31%), State (20%), Agriculture (21%), and Labor (21%) bearing the brunt of the cutbacks.

The White House budget proposal is only the beginning of the budgeting process. Congress will write its own budget, often with little regard for what the administration says. After adopting a budget (which is not required to go to the president for signature), Congress uses its budget as a blueprint to pass a series of appropriations bills, setting the amounts each agency can spend. Under the Senate filibuster rules, passage of these appropriations bills requires sixty votes for passage. To secure the support of Democrats and recalcitrant moderate Republicans, Congress almost certainly will scale back Trump’s proposed domestic cuts -- and, presumably, his additional defense spending -- significantly.

But Congress faces a more imminent deadline. The budgetary procedure outlined above addresses government spending for the 2018 fiscal year, which begins October 1, 2017. Congress, however, has funded the federal government only through April 28, 2017. Thus, before even considering the Trump budget, Congress must appropriate money to keep the government running from May through September.

To do so, Congress is likely to consider a “continuing resolution” (CR), which simply continues government funding during the interim period at current spending levels. As an appropriation measure, a CR also requires sixty Senate votes. Consideration of the CR will be the first opportunity for frustrated Democrats to push back against the Trump agenda. They could be joined in that effort by moderate Republicans Senators, who are concerned that severe cutbacks in social programs would harm many of their constituents.