Last night belonged to the Tea Party and Palinites, who celebrated, ever so briefly, Christine O’Donnell’s upset victory in Delaware. But the professional left, so lovingly characterized by White House Press Secretary Robert Gibbs, isn’t dead yet, either. In an open Democratic primary for New Hampshire’s 2nd Congressional district, progressive candidate Ann McLane Kuster handily defeated self-styled Blue Dog Katrina Swett, who co-chaired Joe Lieberman’s 2004 presidential campaign. Kuster, a lawyer, community activist and women’s health expert, had the support of progressive groups like MoveOn, Democracy for America, Progressive Campaign Change Committee and EMILY’s List. Swett ran hard to Kuster’s right and tried to paint Kuster’s progressive supporters as an electoral liability.

"Annie, you have cast yourself as the very, very progressive candidate and have been warmly supported by the far-left progressive movement," Swett, the daughter of Congressman Tom Lantos and wife of former Congressman Dick Swett, said in the last debate. "In a year when everyone understands that the country is moving back toward the center and away from the more left, progressive point of view, if you were to become the nominee, would you try to distance yourself from your own positions?"

"Actually Katrina, I think it’s your views that are out-of-step with the voters of the 2nd Congressional District," replied Kuster, pointing to Swett’s support for the Bush tax cuts, war in Iraq and escalation in Afghanistan, not to mention her vociferous support of Lieberman in 2004 and 2006. (See Howie Klein for much more on Swett’s background.)

Kuster easily got the best of that argument, defeating Swett by a whopping 42 points last night. She’ll now face GOP nominee Charlie Bass, who held the seat for six terms before losing in ’06 to Paul Hodes, who’s now running for the Senate. Kuster’s big win proves that much of the progressive coalition that unsuccessfully backed Bill Halter in Arkansas still has some juice left. The PCCC lent Kuster staff, donated over $100,000 to her campaign (the average PCCC member donation was $10) and developed her online strategy. EMILY’s List dispatched volunteers to New Hampshire and made thousands of calls on her behalf. DFA and others blasted out emails urging their members to back Kuster. As a result, she’s outraised Bass three to one and is in a much stronger position to win the general election. Kuster, unlike O’Donnell in Delaware, is a polished, capable candidate, not a flaky, scandal-plagued insurgent. (Progressives didn’t fare as well in Massachussets, where incumbent Rep. Stephen Lynch, who inexplicably voted against the healthcare bill despite representing a reliability Democratic seat in Boston, beat back a challenge from labor organizer Mac D’Alessandro.)

NH-02 is still an uphill battle for Democrats, but the seat becomes a whole lot more winnable now that the Democrats’ grassroots base is engaged.