Senate Democrats on Tuesday reached an early agreement to pursue a sweeping $3.5 trillion reconciliation package that would expand Medicare benefits, boost federal safety net programs and combat climate change, aiming to sidestep Republican opposition and deliver on President Biden’s top economic priorities.

The wide array of planned health, education and social programs would represent a historic burst of federal spending if lawmakers ultimately adopt it, as Democrats aim to seize on their slim but powerful majorities in Washington to expand the footprint of government and catalyze major changes in the economy.

Party leaders plan to fashion their agenda using a process known as reconciliation, a move that only requires them to stick together in order to turn their vision into law because it does not require the support of 60 senators. To help rally support, Biden plans to visit with congressional Democrats on Wednesday.

Senate Majority Leader Charles E. Schumer (D-N.Y.) and top lawmakers on the chamber’s foremost budget committee announced the agreement at a late evening press conference. He said “every major program” Biden had endorsed in past economic packages would be “funded in a robust way,” a commitment that comes after the president this spring outlined roughly $6 trillion in jobs and families-focused spending that recommended major new federal investments in healthcare and education.

Schumer added the Senate measure would also feature an expansion of Medicare, adding more federal money for seniors to obtain dental, vision and hearing coverage.

Flanking Schumer, Sen. Mark Warner (D-Va.), one of the centrist lawmakers involved in the crafting of the package, said the budget measure would be fully financed. Democrats previously have said they planned to pay for much of their package using tax increases on wealthy Americans and corporations. Otherwise, the plan will not raise taxes on people making less than $400,000 per year, nor small businesses, according to a Democratic aide familiar with the discussions, in keeping with Biden’s prior commitments.

The measure is smaller than the roughly $6 trillion that some progressive-leaning lawmakers, including Sen. Bernie Sanders (I-Vt.), initially had sought. Sanders, the powerful chairman of the chamber’s budget committee, had led allied lawmakers in arguing for months that Democrats could not afford to squander their seat of power in Washington by adopting a more scaled-down package.

In the end, though, Sanders and his Democratic peers settled on a lesser amount in a move that reflects the political realities inside a party whose centrist wing has sought to temper federal spending in the aftermath of the coronavirus pandemic. Democrats still must also sell the deal beyond those on the budget panel that helped craft it over a series of meetings in recent days. House lawmakers similarly must sync up their own aspirations with the Senate’s plans.

“This is the most significant piece of legislation passed since the Great Depression, and I’m delighted to be part of having helped to put it together," Sanders told reporters late Tuesday. "A lot of work remains.”

Across the Capitol, Democrats see the still-forming reconciliation package as a critical companion to the roughly $1 trillion deal that lawmakers from both parties have brokered to improve the nation’s roads, bridges, pipes, ports and internet connections. In both the House and Senate, Democratic members of Congress have said they would not support the bipartisan infrastructure proposal unless they could consider some of the spending left on the policy chopping block at the same time.

Discussions on that blueprint also proceeded Thursday, as Democrats and Republicans sought to hammer out the finer details of their nearly $1 trillion plan.

In recent days, both efforts had run into potential political roadblocks over their price tags. With infrastructure, for example, lawmakers who returned to the bargaining table on Tuesday confronted the harsh reality of their own math. The financing mechanisms they have chosen to cover the costs of the new spending increasingly do not appear to add up — leaving its chief backers bracing for the potential that the Congressional Budget Office, the official arm of the Capitol that crunches the numbers, could find their infrastructure proposal adds to the deficit.

“We’re doing our best to work through that,” said Sen. Susan Collins (R-Maine) as she exited a roughly two-hour gathering.

Collins and other participants said the group had set a loose Thursday deadline by which they hope to resolve their substantive differences and start turning their ideas into an actual bill. Asked if the fiscal issues had strained the bipartisan effort, Collins added: “I don’t think that we have lost anyone.”