Sen. Bernie Sanders (I-Vt.) is facing a gut-wrenching decision about whether to sign off on a whittled-down budget reconciliation package that is expected to fall short of his goal to expand Medicare and empower the federal government to negotiate lower prescription drug prices.

Sanders has urged his party to be as bold as it was in the 1930s when President Franklin D. Roosevelt dramatically expanded the size and role of the federal government, but the package that is emerging after weeks of fitful negotiations won’t come close to that ambitious call to action.

Getting Sanders, the chairman of the Senate Budget Committee, on board with the scaled-down reconciliation bill is imperative for Senate Majority Leader Charles Schumer (D-N.Y.), who can’t afford a single defection within his caucus in the 50-50 Senate.

If Sanders agrees to the deal, other progressive Democrats in the House and Senate are likely to follow his lead and swallow their disappointment that the legislation no longer includes a clean electricity program and 12 weeks of paid family leave.

Sanders is also viewed as the key to unlocking progressive votes in the House for a $1 trillion bipartisan infrastructure bill, which has been stuck in limbo while liberals wait for a deal they can accept with centrist Sens. Joe Manchin (D-W.Va.) and Kyrsten Sinema (D-Ariz.) in the upper chamber.

But he won’t be thrilled to embrace the emerging deal based on the current trajectory of the talks. Over the past several weeks, the package has moved further and further from his ideals. 

“I think it will be a very bitter drink, if it goes down at all. There are certain red lines that have been crossed as far as Sanders is concerned,” said Ross K. Baker, a professor of political science at Rutgers University, who has held several fellowships in the Senate.