Failing to enact a package akin to the one he initially proposed might also disappoint the president, who hoped the gravity of these challenges and the trauma inflicted by the pandemic would create a rare opportunity to pass an agenda as bold in scope as Franklin D. Roosevelt’s New Deal.

But the math is the math. In a 50-50 Senate and an evenly divided House, there are obvious limits to what can be achieved. Even Roosevelt took years to enact the New Deal.

To paraphrase F.D.R., it’s time for a rendezvous with reality, and fight for what is possible.

Mr. Manchin has said at various points that he could support a scaled back bill that made long-term commitments to fewer priorities. If there is a chance to make prekindergarten the standard in America, with all that would mean for children today and in the future, it would be a remarkable achievement. Expanding and strengthening the A.C.A. or making permanent a more targeted child tax credit, dramatically reducing the number of children living in poverty in America, would mark monumental progress. Paying for it by offsetting or even partially repealing the Trump tax cuts of 2017 would be fair, equitable and a major step forward.