Here’s What to Know About Congressional Republicans’ Budget Plans

The Senate on Tuesday evening voted on party lines to adopt a budget outline designed to clear the way for a major piece of President Trump’s domestic agenda, putting forth a measure that calls for increasing spending on immigration enforcement and defense while cutting other federal programs.

Republicans in Congress have been consumed for weeks with advancing a budget blueprint to power their push to enact Mr. Trump’s sweeping tax and immigration agenda. Approval of such a plan is a crucial first step if Republicans want to avail themselves of a process called budget reconciliation, which allows legislation that affects government revenues to pass the Senate on a simple majority vote.

For decades, both parties have used that maneuver to push major domestic policy legislation through Congress — including tax cuts, health care policy changes and economic relief packages — over the opposition of the minority party. The stakes are exceedingly high, and the process is tremendously difficult.

The House and Senate, both controlled by Republicans, have been working on separate budget plans and are at odds on how to move forward. With the House G.O.P. divided and delayed in considering their outline, the Senate is moving ahead.

Here’s what you need to know about the budget.

What is a budget resolution?

In theory, Congress is supposed to adopt a budget resolution each year setting a top-line number for federal funding and providing general contours for how that money should be spent. After the plan is approved, it falls to lawmakers on the Appropriations Committees to allocate federal dollars, following the blueprint.

Lawmakers in recent years have not produced such a plan or put it to a vote, sidestepping tough decisions about what programs to spend on and what programs to cut. Instead, congressional leaders, in collaboration with senior appropriators, have agreed on the overall numbers and simply passed spending legislation each year.