Senate Democrats reached a breakthrough this week on a $3.5 trillion package that includes massive new spending on a range of health, education and federal safety net programs endorsed by President Biden and progressive lawmakers.

Republicans have opposed many of the proposals in the plan, but Democrats intend to move this legislation via the budget reconciliation process which will only require 51 votes to pass. Senate Majority Leader Chuck Schumer (D-NY) said part of the package will expand Medicare, funding new dental, vision and hearing benefits while lowering the cost of prescription drugs. Schumer and other top Democrats said at a press conference this week that they will pay for the package through new taxes on corporations and wealthy families, a move that will be a non-starter for most if not all Republican lawmakers.

“This is the most significant piece of legislation since the Great Depression, and I’m delighted to be part of having helped put it together,” said Sen. Bernie Sanders (I-VT), adding, “A lot of work remains.”

The $3.5 trillion in spending is larger than some moderate Democrats want but smaller than liberal lawmakers such as Sanders initially wanted. Yesterday, one of the party’s most influential swing votes, Sen. Joe Manchin (D-WV), said he is waiting to review the fine print while adding that a key factor for him will be whether the bill is fully paid for.

“I’m open to looking at everything they provide,” Manchin said. “We’ll look at the proposal, look at the priorities they have for our country, and then basically look at how we’re going to pay for it.”

While details of the package have not been released, White House officials have confirmed that it will be fully paid for and will include new taxes on corporations and the wealthy, while sticking to Biden’s pledge not to raise taxes on anyone making less than $400,000 per year.