Former Democratic National Committee chairman Howard Dean is emerging as a thorn in the side of a White House that effectively swept him out of Washington, regularly challenging President Obama and Congress as he crisscrosses the country, preaching his progressive vision for universal health care. 'The worst thing that could happen is to pass a bill without a public option,' Dean told an assembly of Democratic activists in a fiery speech at a pep rally and picnic here last weekend. 'Then we'd put 60 billion new dollars a year into the health insurance industry that is busy taking away your health insurance when you need it most, stopping you from getting health insurance, taking it away if you lose a job and not giving it back to you if you get it back.' Some 200 union workers and Democratic volunteers who knocked on doors and tirelessly turned out voters for Obama last November rallied here Sunday behind a different leader. With Obama seeming to back away from a public option in his health-care-reform plan, the liberals embraced Dean as their spokesman of the moment as he asserted that reform without a government-run insurance option is hardly reform at all. 'We all voted for change we can believe in. If we don't get it, we'll get some more change in 2010,' Dean roared, the crowd applauding. At town halls, in keynote speeches and on cable talk shows, Dean has become a leading voice in the debate, warning that if Democratic leaders abandon a public option, they surrender their principles to political realities. But in his appearances, which are not coordinated with the administration, Dean is helping to fuel what could become a calamity for the White House. 'What Howard is doing is principled but destructive,' said a Democratic strategist and former Dean adviser who spoke on the condition of anonymity because of the sensitivity of the intra-party debate. 'If health-care reform goes down because of the public option, it's going to be the liberals that bring it down, the Democrats doing it to themselves.' Dean, 60, has become a politician without an office. Seven months removed from the DNC chairmanship and five years removed from his pioneering up-start presidential campaign, the former family physician apparently enjoys the freedom to speak his piece. On this day, bringing the tumultuous August fight on health care to the picnic benches at Range Ponds State Park, he did not appear concerned about the potential consequences for Obama. 'This vote is not about Democrats versus Republicans and conservatives and liberals and all that stuff,' Dean said. 'This is about whether you're going to vote for the people who donated to your campaigns -- the health insurance industry -- or you're going to vote for the people who pay your salary. And we're going to be watching, because there are going to be 535 people casting that vote.' Obama's apparent willingness to appease moderates has angered many in his liberal base. And while conservative town-hall hecklers did not trail Dean here, the atmosphere was heated Sunday as many at the Androscoggin County Democrats picnic showed their displeasure with any health-care deal that does not preserve a public option. 'I would like to see single-payer health care in this country,' said Randy Huber, 64, a retired state government worker from Canaan. 'To me, the public option is only a start.' Marianne von Nordeck, 29, a labor organizer from Portland, added, 'We think real reform means a public option, and (Dean) has the freedom to get up there and advocate with us.' Progressive Democrats in Congress, and the volunteer activists who helped put them there, revolted this week over comments from top administration officials that Obama was willing to give up a public insurance option to strike a deal on health care with congressional moderates. Some are frustrated after working for years to help Democrats win back the White House and big majorities in Congress. 'They are like, `What's the fruit of our labor?' ' said Joe Trippi, a Democratic strategist who managed Dean's 2004 campaign but has since feuded with him publicly. 'Howard's giving that voice. ... He's definitely speaking out for a legitimate, sizable portion of rank-and-file progressives.' Dean received a hero's welcome when he addressed hundreds of progressive bloggers last week at the Netroots Nation convention in Pittsburgh. He was their favored messenger in 2004, when his innovative campaign fueled the rise of the 'netroots' in the Democratic Party. Now, five years later, Dean is speaking for them again. 'The president has put together the best health-care (proposal) I've ever seen,' Dean said. But, he added, the public option itself is a compromise between liberals who supported a government-run single-payer system and moderates. 'We have already made our compromise, and there will be no more compromises in this bill.' (Begin optional trim) In a wide-ranging interview Sunday, Dean said he is energized by his appearances, many of which are organized by the Service Employees International Union. But when asked whether he sees himself as a spokesman for the progressive wing of the party, he said, 'I don't spend a lot of time seeing myself in general.' A family doctor for two decades, Dean has a unique perspective on the issue. In 1991, then-Lt. Gov. Dean was examining a patient when he received a call telling him the governor had died and that he would take over. As governor, he helped pass laws ensuring near-universal coverage for residents under 25. 'Health care was the primary driver of him getting into politics a long time ago, and it certainly was a signature of his governorship in Vermont,' said his brother, Jim Dean, who chairs the Democracy for America political action committee. 'He's very committed to getting health care for everybody. He tried it nine ways, sideways, here and angled a way to do it for kids. But he really views this as being a core issue for him.' Dean's wife, Judith Steinberg, whom he met in medical school, still has a medical practice near their Burlington, Vt., home. 'The insurance companies are driving her crazy,' Dean said in the interview. 'I think her experience is very typical of most primary-care providers.' (Begin optional trim) Dean took a few shots at the Obama administration's handling of the current debate. 'I think that there's a very mixed message coming out of the administration,' he said. 'What I'm selling is something that's really clear.' What Dean is selling is his latest book, or at least the proposal outlined in it. 'Not to shill for my own book, but if you have $12.99 or whatever it is to spare, `Howard Dean's Prescription for Real Healthcare Reform' actually explains all this in plain English in about 130 pages, and you can get through it in a good afternoon,' he told the Poland Spring crowd. As DNC chairman, Dean campaigned hard for Obama, and former aides said he was interested in working for the administration. Asked if he would rather be in Washington, Dean demurred but did not hesitate to tout his credentials. 'I know this stuff from a public policy point of view pretty well inside out,' Dean said, 'and I've also got a reasonably good political sense.' 'I think Howard Dean would've loved to have been in the room hashing out health-care reform, whatever the role,' Trippi said. 'I think he would've relished that. He's passionate, he's a doctor, he knows it. But, look, that wasn't in the cards, and to his credit he didn't walk away. He's leading the charge on issues he cares about.' 