I’ll admit that like almost everyone in this town, I thought the public option was dead. In late October when Joe Lieberman announced he’d filibuster any bill that included it, I figured it was time to conduct an autopsy (cause of death: blows administered in quick succession by an obstinate insurance industry and "centrist" senators), commence the mourning process and move on.

But now, improbably, the cadaver is twitching and kicking, threatening to push its way out of the casket. As of this writing, twenty-four Democratic senators have signed a letter calling on majority leader Harry Reid to include a public option in the package of changes the Senate will pass through reconciliation. The list of signers isn’t just made up of the usual progressive suspects; the letter was written by Colorado’s Michael Bennet and signed by New York’s Kirsten Gillibrand–neither known for a commitment to the progressive base–and has attracted the support of conservative Democrat Tim Johnson and the extremely politically savvy Chuck Schumer.

This doesn’t mean it’s going to work. Jay Rockefeller, who had advocated strongly for the public option when it was being debated in the Senate, dismissed the possibility of passing the public option through reconciliation, and the White House quite ostentatiously omitted it from its proposed changes to the Senate bill. Their lack of support has to be read as opposition.

And yet, the public option is like the Terminator of progressive politics: every time the insurance industry and conservative Democrats think they’ve killed it, it just keeps coming.

Why does it persist? First, people like it. Despite relentless scaremongering about government-run healthcare, poll after poll shows that among independents and progressives, it’s one of the most popular–if not the most popular–parts of the entire healthcare reform package. Second, it’s good policy. It would mandate competition, reduce costs and cut the deficit by $104 billion over ten years.

But in the dysfunctional institution that is the US Congress, popular and good aren’t enough to ensure a proposal’s passage, or even its discussion. What’s really kept the public option alive has been the remarkably spirited, disciplined and creative work of a variety of progressive groups.

Take this latest iteration. It started with a few activists at the start-up Progressive Change Campaign Committee. PCCC has been around only a little more than a year, but it’s already had a significant impact, thanks to its smart tactical approach and very small footprint. Started by former MoveOn organizers, the group has a staff of nine and, like MoveOn, raises all its money from members online.

In the wake of Scott Brown’s victory in Massachusetts and the chaotic, shellshocked response from Democrats, PCCC saw a vacuum and moved to fill it. "People didn’t know what to do," says PCCC’s Stephanie Taylor, "so we showed them through polls, which is the language they understand." PCCC commissioned polls of Massachusetts Obama voters who had voted for Brown, as well as voters in ten frontline Democratic Congressional districts, and found widespread support for the public option in each. In concert with PCCC and its partners Democracy for America (DFA) and Credo Action, two freshman Democratic House members, Jared Polis and Chellie Pingree, wrote a letter calling on Reid to include the public option.

"If the Senate is going to pass something with a straight up-or-down vote," asks Taylor, "shouldn’t it be the best bill possible? The one that’s best politically and that’s best policy-wise?"

On January 27, PCCC, DFA and Credo sent news of the letter to their e-mail lists and urged members to contact their representatives. They set up WhipCongress.com, where users could track who had signed on, and within eight days the letter had attracted 120 signatories in Congress. "There’s no doubt we would have had far less than 120 signers without the netroots community," says Polis. "The phones were really ringing off the hook in members’ offices." Not only did progressives use constituent contact to push members to support the public option; they also, Taylor notes, went out of their way to reward their "heroes," raising more than $26,000 each for Polis, Pingree and Alan Grayson, who appeared at an event delivering petitions to Reid.

They then turned their attention to the Senate. According to PCCC’s Adam Green, Polis reached out to fellow Coloradan Michael Bennet, who had been a supporter of the public option. Bennet released the letter along with signatures from Jeff Merkley, Sherrod Brown and Gillibrand. Once again, the groups sent the letter out to their members and urged them to whip the Senate, and within a week of its release, it has gained twenty-four co-sponsors. Once again PCCC and DFA rewarded those who took the lead, raising $40,000 for Gillibrand and $68,000 for Bennet. Reid now says he’ll include a public option in reconciliation if he can get the votes–and White House support. But the White House’s silence has been deafening. That’s at least part of the reason why, by the time you read this, it’s quite possible the public option will be dead, once again.

But PCCC’s success in reopening the debate highlights some of the emerging approaches in online organizing. Much of the recent online-based progressive infrastructure was built during the Bush years and developed effective strategies for opposition. It’s been a steep learning curve this past year as these groups wrestle with reinventing those techniques to push legislation, especially when it comes to finding allies in Congress and then working with them. "I think this campaign was a really good example of the importance of a strong relationship between folks on the Hill and activists outside the Hill," says Taylor. "We put a lot of time and attention on those relationships." Pingree agrees: "Things always work best when you have an inside/outside strategy."

The incentives on Capitol Hill push toward risk aversion, minimalism and conservatism. The job of progressive activists, as PCCC understands it, is to alter those incentives and encourage those who go out on a limb. "Members want to be bold," says Taylor, "and they need to know they have grassroots constituent support."