“The costs of inaction are incredibly steep, incredibly lasting … We have to balance the cost of the plan against the cost of inaction,” said Jared Bernstein, a member of the White House Council of Economic Advisers, at a Washington Post Live event, arguing delay could mean 4 million fewer jobs in the U.S. this year. “The cost of inaction is the reason for our urgency.”

The House passed the budget legislation on Wednesday, with all Republicans opposed. Under the Senate’s arcane rules, debate on the budget resolution in the Senate will trigger a freewheeling amendment process known as a “vote-a-rama” that begins Thursday afternoon and could last overnight into Friday morning, since there is no limit on amendments.

Republicans will use the opportunity to force Democrats to vote on politically tricky issues such as stimulus payments to undocumented immigrants or funding for schools that have not reopened to in-person learning.

But it is all but destined to end with the Senate passing the budget resolution, which contains instructions to congressional committees to draft the actual relief bill. The House plans to immediately pass the Senate version, and Congress will then be on track to finalize the work of writing the relief legislation in earnest — even as the Senate turns its attention to Trump’s second impeachment trial.

Democrats are eyeing a mid-March deadline for passing the final relief package, since that’s when enhanced unemployment benefits expire without action.

“We’re in one of the greatest crises America has ever faced,” said Majority Leader Charles E. Schumer (D-N.Y.). “If there are good-faith amendments from the other side, we look forward to them. What we cannot do, however, is think small in the face of big problems. We cannot repeat the mistakes of the past. We cannot do too little.”

Moving forward under the “budget reconciliation” process allows the relief bill to pass the Senate with a simple majority vote, instead of the 60 normally required. That will allow Democrats to move forward with no GOP votes if necessary, although Democrats and Biden officials insist that they hope Republicans will join them.

Biden’s efforts to craft a bipartisan deal have been minimal, however. He met Monday evening with 10 Senate Republicans after they offered a $618 billion counterproposal, but the White House never indicated willingness to move off Biden’s $1.9 trillion top-line or seriously consider a bipartisan compromise.

The few elements of the legislation that Democrats are looking at scaling back — including who would qualify for a new round of $1,400 stimulus checks — appear designed more to keep their own party unified than attract GOP votes. The Senate is split 50-50 between the two parties, with Democrats in the majority because Vice President Harris can break ties. So Democrats cannot lose a single vote if Republicans oppose them, giving moderate Democrats like Sen. Joe Manchin III (D-W.Va.) great influence in the process.

“There’s nothing about unity in this exercise. This is designed to be a partisan exercise, it is designed not to find common ground,” said Sen. Patrick J. Toomey (R-Pa.). “The only organizing principle in this bill I can figure out is a desire to spend a massive amount of money on things that are not required.”

Republicans themselves used the budget reconciliation process to pass their massive tax cut bill at the start of the Trump administration. The process has limitations, since certain provisions that don’t have an impact on the federal budget can be challenged and struck from the legislation. Some outside experts believe Biden’s proposal to raise the federal minimum wage to $15 an hour could be at risk, for example.

In addition to raising the minimum wage and sending out a new round of stimulus checks, Biden’s proposal would increase the child tax credit, extend enhanced unemployment benefits through September, provide rental assistance and money for nutrition programs, send $130 billion to schools to help them reopen and allocate $160 billion for a national vaccination program, increased testing and other spending in the health care sector.

The debate comes against a backdrop of continued high unemployment and a slower-than-desired vaccine rollout even as new variants of the coronavirus emerge. But Republicans argued against spending more money after already devoting $4 trillion to fighting the pandemic, including $900 billion in the most recent legislation in December.