As lawmakers in Congress continue negotiations for a multi-trillion dollar domestic spending bill, Congressman Paul Tonko highlighted his support for a key component of the plan. 

And some representatives are back in district supporting President Joe Biden's domestic agenda in Congress is hinging on a major package of spending proposals ranging from funding pre-Kindergarten to boosting Medicare benefits. On Monday in Albany, Rep. Paul Tonko pointed to an expansion of the child tax credit that could be included in the final bill.

"Child care has not been under attack as some elements of the build back better program," Tonko said. "So I believe we'll get to a sound consensus.”

To pay for the plan, Democrats have proposed tax increases on upper income earners and corporations over the next decade. 

"Build Back Better has a payment mechanism attached to it," Tonko said. "So as we go forward, I think that helps the negotiations to know there's this balancing act going on and there's a responsible way to building back better."

But passage of the legislation, broad in scope that could remake how Americans interact with social safety nets, is far from certain. Drumming up support with Tonko on Monday was Congressman Hakeem Jeffries, widely seen as a successor to House Speaker Nancy Pelosi. 

"The next few weeks will be critical and failure is not an option," said Jeffries, a Democrat from Brooklyn. 

Adding to the complications around the negotiations is the opposition from some Democrats who consider the plan too expensive. There's little margin for error given the narrow majorities Democrats hold in the House and Senate. 

Still, Democrats point to the earlier COVID-19 stimulus measure passing despite their small majorities in both chambers of Congress, and expect to be able to do it again. 

"We were able to come together in the past most recently around the American Rescue Plan and we will do exactly the same thing with the Build Back Better Act," Jeffries said. 

Advocates for expanding the child tax credit like the Schuyler Center's Kate Breslin point to the effect the move would have on low-income families and among people of color who have struggled during the pandemic. 

"Sacrificing this expansion would literally take money away from families experiencing deep poverty -- families who struggle every day to keep the lights on, their children housed and clothed," Breslin said. 

The clock is ticking, however, as Democrats set their sights on the next self-imposed deadline of Oct. 30 to get the bill done. After that, the political calendar could take hold, potentially closing a window of opportunity ahead of what could be a difficult election season for Democrats.