Like so many progressives who have fought for a public option plan which privileges the all-American principles of choice and competition, I am both heartbroken and outraged as Joe Lieberman–Senator Aetna himself–dominates negotiations on the final Senate bill.

The healthcare situation is a desperate one, with 46 million people uninsured, and those who are insured at the mercy of profit-maximizing Big Insurance. The raw politics of our time–including a GOP hell-bent on crippling and bringing down Obama’s presidency and corporate Democrats who do the bidding of lobbyists–makes getting a good healthcare bill all the more difficult. Ours is not a parliamentary democracy. There are limits to what the majority can achieve.

We progressives are not so naive as Rahm Emanuel would have the American people believe. Most of us understand the need for compromise in this system. But, as I wrote earlier this year in a Nation cover story, while "compromise is inevitable. The hard question is whether the compromise opens the door to greater progress or forecloses opportunity." The White House mantra is "don’t let the perfect be the enemy of the good." Yet as I argued, "The danger is that this process may make the weak the enemy of the good."

Throughout our history, real reform has come in fits and starts. Witness Social Security and Medicare. As Paul Begala observed in a Washington Post op-ed, "No self-respecting liberal today would support Franklin Roosevelt’s original Social Security Act…If that version of Social Security were introduced today, progressives like me would call it cramped, parsimonious, mean-spirited and even racist. Perhaps it was all those things. But it was also a start. And for 74 years we have built on that start."

Along those lines, there is indeed some good in this bill. It represents the largest expansion of coverage since Medicare’s creation with 31 million previously uninsured Americans gaining insurance. For low income Americans, the bill offers the largest single expansion of Medicaid since its inception, and subsidies for middle income families will ensure that they have access to basic health care coverage. This historic expansion is 30,000,000 of the very people progressives seek to help. This will provide millions of more people coverage than the public option ever would have helped.

But in this defining moment key choices lie ahead: do we accept that Senator Aetna–after he flip-flopped on his previous support of a Medicare buy-in–decides what kind of a bill emerges in the end? Do we accept the anti-democratic vise of the filibuster and the unwillingness of Senate Majority Leader Reid–apparently under terrific pressure from Rahm Emanuel and a White House desperate for a bill of any kind–to try reconciliation which has been used over 20 times by the Party of No to pass legislation? Do we give up on the compromise of a compromise–Medicare expansion as the alternative to a robust public option which was a compromise to Medicare for All/single-payer?

This fight is still very much on.

Progressives need to push back right now and demand something better. The House and Senate must go to conference to meld the two bills, and the House bill is better on Medicaid expansion, affordability, the anti-trust exemption for insurers, and financing through taxing the wealthy rather than taxing middle-class healthcare benefits. The Progressive Caucus, which is the largest caucus in Congress and has played a critical role in fighting for the public option–has spine. This is a moment to flex and strengthen it.