Congress Strikes Long-Sought Stimulus Deal to Provide $900 Billion in Aid

As congressional leaders clashed over their competing priorities for another round of aid, coronavirus cases surged, millions of Americans slipped into poverty and countless businesses, restaurants and performance venues shuttered as their revenues evaporated amid the pandemic.

“There is no doubt this new agreement contains input from our Democratic colleagues — it is bipartisan,” said Mr. McConnell, who initially resisted another stimulus package, saying that Congress should pause and consider the deficit before providing more relief. “But these matters could have been settled long ago.”

Emboldened in the aftermath of the November election, a bipartisan group of moderates brokered their own $748 billion compromise, pressuring congressional leaders to redouble their efforts to find a deal. Ultimately, the top two Democrats and top two Republicans on Capitol Hill, huddling with their staff and at times Steven Mnuchin, the Treasury secretary, wrangled the final agreement over a few chaotic days the week before Christmas.

The deal was far narrower than the one Democrats had long insisted upon, and nearly twice the size of the one Republicans had said they could ever accept in the days leading up to the November election.

At the core of the breakthrough was a mutual agreement to drop critical priorities championed by one party and loathed by the other: a Democratic push to establish a direct stream of funds for cash-strapped state and local governments, and a Republican demand for sweeping liability protections for businesses, hospitals and other institutions open during the pandemic.

But it nearly fell apart as Democrats sought additional avenues to provide relief to state and local governments suffering significant revenue shortages, and as Republicans fought to limit the power of the Federal Reserve to provide credit to municipalities, businesses or other institutions, as it has done this year through an array of emergency lending programs intended to stabilize the economy during the pandemic in times of crisis.

Senator Patrick J. Toomey, Republican of Pennsylvania, mounted a last-minute push to ensure that those programs would end and prevent the Fed and Treasury Department from setting up any similar one in the future. Democrats balked, arguing that the move would deprive the Fed of critical tools for bolstering the economy, and tie Mr. Biden’s hands as he confronts a daunting public health and economic crisis.