Health and Human Services Secretary Kathleen Sebelius created a firestorm among liberal pols and activists when she reiterated on Sunday that the White House, while supportive of the public option, does not view it as "the essential element” for health care reform. On the airwaves and in print, lefty commentators blasted the Obama administration for its newest hedge, including Washington Post columnist Eugene Robinson, who wrote that "we didn't elect Obama to be an expedient president." Meanwhile, 60 congressional progressives sent a letter again warning they would vote against any bill -- either the House version or the conference report -- that does not include a public option. Unlike the last letter, which was sent to Speaker Nancy Pelosi in late July, this version landed on Sebelius' desk and included three more signatories. And netroots activists are raising money to "reward" lawmakers who stand by their promise.

The main concern of House progressives like Rep. Jan Schakowsky is that any co-op model created by the conservative Senate Finance committee would be too small and fragmented to provide real competition to the insurance companies. At least 500,000 people would have to join the non-profit insurance pools, according to estimates from Sen. Kent Conrad (D-North Dakota), before they would be powerful enough to negotiate reasonable prices with health providers. As Ezra Klein wrote yesterday, "the co-op does not solve a policy problem so much as it solves a political problem." That problem, of course, is finding a compromise that public option critics -- those who don't believe a public insurer limit costs and provide access to high-quality care better than the profit-driven private system -- can support.

Will it work? Republican obstructionists, including Rep. Peter Roskam, have already decided that the alternative is equitable to government-run health care and won't back the plan because that provision was included. "We have to make sure [the public option] is really off the table," Roskam said on WLS' Don Wade and Roma yesterday, "and not recast with a different name." Activists raging against the plan aren't going to ease up, either. At a health care town hall last night in Moline, Rep. Phil Hare expressed some openness for the co-op proposal. For that, he was rewarded with one taunt that he was a "socialist."

A bill with co-ops would likely gain enough support in the Senate Finance Committee, however, clearing the way for two full chamber votes and the possibility of intense conference negotiations. Ultimately, Congressional leaders are going to have to take a gamble. Should they include a public option in the final bill, knowing that some Senate Dems may do the unthinkable and join Republicans in a filibuster of President Obama's major campaign plank, or risk losing the support of reformers in the House? For those in the latter camp, the stakes are probably too high to miss another chance at extending coverage to the vast majority of Americans. After all, it's easier for lawmakers to strengthen than write a new law. But their public pressure at this crucial stage is valuable if it keeps all options -- public or otherwise -- on the table.