Democrat Elizabeth Warren waves to the crowd before giving her victory speech after defeating incumbent GOP Senator Scott Brown in the Massachusetts Senate race, during an election night rally at the Fairmont Copley Plaza hotel in Boston, Tuesday, November 6, 2012. (AP Photo/Michael Dwyer)   Massachusetts just sent the US Senate a pure and passionate voice for an unwavering progressive vision.   They were insane at the Warren party in a gilded ballroom at the Fairmont Copley in downtown Boston. I’ve never spent election night with a campaign before, but I don’t think I’ll ever spend election night at home alone again. With two huge screens up front cycling among the regional cable news and various TV news stations, the screams got louder every time the numbers flashed on screen. Every color that you can find in Massachusetts was here: ruddy faces descended from the Irish, gray no-product hair and purple fleece vests from the People’s Republic of Cambridge, young white guys with square glasses and cool sideburns, Harvard law students in sleek suits and perfectly plucked eyebrows, black guys in dreads, a range of brown tones from South Asia to south of the border. Shoulder to shoulder, so jammed it was hard to make it through the room, they were beaming, grinning, screaming like rock fans, delirious with glee.

They roared with happiness at all the small New England victories: Congressional seats, Connecticut’s Senate seat, New Hampshire’s delegation. They roared every time Obama won another state: Vermont, New Hampshire, Michigan.

Then it came: CNN called it for Warren, up there on screen. I thought my eardrums would pop as they screamed, fists in the air. An graying woman in purple fleece roared, “The people got their seat back!” The sound system played Bruce Springsteen, of course, now mandatory for all Democratic functions: “no retreat, baby, and no surrender.”

Warren’s win—like the marriage equality wins in four states—was a victory for the grassroots organizing philosophy championed by state party chair John Walsh, Michael Dukakis and Deval Patrick, which I reported on here two weeks ago. As Patrick roared from the Warren ballroom stage last night in a call-and-response session to a roared response, “This election said that conviction matters (yes!), the grassroots matter (YES!), not just as strategy but as a philosophy: we believe you have to engage everyone, everybody has a place in making our commonwealth and country strong.” The state party and the national party worked together to create a streamlined door-to-door and volunteer phone-banking machine that reached nearly one-fifth of the state, reaching out to at least a million contacts. When I reported on the campaign last spring, a mid-state Worcester Democratic town committee member told me that Warren would “single-handedly revive the Massachusetts Democratic Party .”

Her political passion, authenticity, sheer charisma and clear-as-a-bell progressive beliefs brought in an astonishing number of volunteers, many of whom had never done anything before for a political campaign. In the first months, the campaign was overwhelmed, but by June the state party was putting everyone to work knocking on doors and making calls, with an incredibly simple script, keeping track for the get-out-the-vote system to come in the final week and on Election Day, as The Boston Globe reported in depth. The system, which Walsh and Patrick and others envision as a way to restoring politics to people rather than screaming pundits, worked so well that it could—and should—be a model for the rest of the country.

Now Elizabeth Warren is going to Washington as the senator of the left. After Michael Dukakis, Deval Patrick and John Kerry lined up to introduce her, to escalating off-the-chart roars from the delirious crowd, the future senator herself came out. “You go, girl!” someone yelled, and she laughed so hard she could barely stand. “This victory belongs to you!” she said, beaming like a sun. “Let me be clear: I didn’t build that—YOU built that!” The cheering slashed through my eardrums. From the stage, she called out, “For every family that has been chipped at, squeezed, and hammered, we are going to fight for a level playing field, and we are going to put people back to work. To all the small-business owners who are tired of a system rigged against them, we are going to hold the big guys accountable. To all the seniors who deserve to retire with the security they earned, we’re going to make sure your Medicare and Social Security benefits are protected, and that millionaires and billionaires pay their fair share of taxes. And to all the young people, to all the young people who did everything right and are drowning in debt, we’re going to invest in you. To all of the service members and your families who fought so hard for us, we’re going to fight for you.”

“We love you!” someone cried out.

“I love you!” she cried back.

“And to all the women across Massachusetts—“ They cut her off. They screamed and whistled and whooped for nearly a minute: she’s never said it, but she knows, and we know, perfectly well that she is the first woman stodgy Massachusetts has ever elected to the Senate. “To all the women in Massachusetts who are working your tails off, you better believe we are going to fight for equal pay for equal work.”

You’ve heard her credo. You’ve seen her ruthlessly interrogate Timothy Geithner, the banker’s champion. She has the charm to work with anyone, the ability to negotiate the small things, and the relentless ferocity to push through the large things. She may be a junior senator, but there’s no doubt that she will help energize and rally the newly expanded progressive caucus—yo, Tammy Baldwin! She’ll attract and inspire talented staff who’ve been dying to actually do something in Washington, pulling for a genuinely progressive tax code, for regulations that restrain rapacity and keep consumers in mind, for investment in education and infrastructure, for women and LGBT folks and service members and retired people.

There was more. At one point, she sounded like she was going to cry. She promised never to forget all the stories she had heard on the trail, and promised: “I won’t just be your senator. I will always be your champion!”

Read George Zornick on Obama’s agenda for his second term.