Last night I was privileged to participate in a conference call with Senator Kerry meant for Massachusetts bloggers who wanted to hear about his campaign for reelection to the Senate later this year. And I realized, listening to him, that the theory I’ve been nurturing lately is absolutely true: John Kerry has never stopped being the grassroots activist he was before he began his political career.

We’ve all been involved in some grassroots effort and we know how it works: it’s a matter of vision, goals, organization and sheer grit. You’re fighting some form of City Hall, usually, and the only way to fight an institution that has all the power you lack is — every which way you can think of! That means demonstrations, door to door work, phone calls, flyering, rallies, letters to the editor, blog entries, media attention if you can get it. It means getting the truth out past the machine that is trying to shut you down. It requires ingenuity and relentless determination. Lots of the time you have to lose and get right back up again and keep going ’til you finally get to victory.

I knew John Kerry had done all those things when he was a young veteran, just returned from Vietnam, first working to make a safe, healthy environment, helping to organize the very first Earth Day in 1970, and then speaking out on college campuses and on the Dick Cavett Show and in front of the Senate Foreign Relations Committee, speaking out to defend his brothers in arms, those still dying overseas, and those who had returned home scarred in body, mind and spirit. He was an organizer and an activist in those movements, and a highly effective one whose success worried the Nixon White House into a personal attack campaign against him.

Since that day in November 2004 when he bravely conceded a narrow defeat in his fight for the presidency and I watched him get back up and start working again toward his goals for Massachusetts and the nation, I’ve been realizing that everything he does is still in that grassroots activist mold. He is still fighting City Hall to get the truth out to the American people and he still uses every means open to him. That means filibustering Alito and being one of the earliest and strongest voices to tell us the smart way to be successful in Iraq and Afghanistan without continuing to put our brave troops’ lives in harm’s way. That means speeches on the Senate floor, but also blogging and the print and broadcast media and internet outreach through e-mail and his online PAC blog and website and offshoot sites like the Roadblock Republicans.

It means an incredible record of legislative achievement (dearly won in the last eight years of Republican partisanship.) It means tireless campaigning all over the country, first in 2003-4, then in 2006 when he stumped for so many Democratic Congressional candidates, throwing himself more than any other politician into the successful effort to win back the majority. It means op-eds and Letters to the Editor, which he regularly writes, it means taking to blogging and bloggers like a natural (go here for a telling exchange with a Daily Kos commenter who couldn’t imagine a grassroots Senator but was convinced!) It means endorsing a candidate like Obama when he’d just lost New Hampshire, and then backing that endorsement up with the same kind of all-out commitment and endurance he showed in his presidential campaign and his fight in 2006 to win back the Congress. This time, what’s at stake is the White House, an essential element in the Democratic fight to put our country back on course, and he’s showing his activist roots again: defeat doesn’t mean you’ve lost: go for victory another way.

This is the John Kerry we heard in our blogger call last night. He was in the Senate, waiting for an evening vote and despite having just come off an impossibly grueling schedule (Afghanistan Friday at the end of a four-country week, Texas stumping for Obama Saturday, back to Boston and events here Sunday, and then to D.C. Monday,) he sounded alert and cordial.

We asked him about his Senate campaign and he talked about how he’s been crisscrossing the state, talking to mayors and business people and citizens in every community. The common issues start with an economy that’s in deep trouble after the subprime mortgage crisis — that extends to every aspect of Massachusetts families’ lives — from healthcare costs to housing to winter fuel expenses and food bills. As always, he’s deeply involved in working for veterans’ needs and equal opportunity for the small businesses that are the lifeblood of our economy. After enumerating some of the challenges we face, he talked about the vision he shared with the country in 2004, many aspects of which we’re seeing in the platforms of our current candidates, from energy independence and green jobs to healthcare solutions to tuition in exchange for community service to a foreign and trade policy that thinks globally but always puts American interests in the foreground. Those ideas are part of his legacy as a candidate and he’s happy to see them in the current race. His other legacy is the grassroots spirit and inspiration of young voters that was his other strength in 2004. We’re seeing that in the Obama campaign and very much in Senator Kerry’s own involvement and this time we’re lucky enough to have a Howard Dean DNC with a 50 State Strategy grassroots strategy that backs that up instead of a Terry McAuliffe DNC that was the antithesis of the grassroots.

Kerry was in a playful and optimistic mood during the call. At one point he excused himself saying “Senator Rockefeller is harrassing me!” We heard him thanking the Senator and he came back to explain that Rockefeller had seen his C-SPAN appearance over the weekend stumping for Obama in Galveston, Texas, and wanted to compliment him on his town hall speech and Q&A session with voters.

We asked him about the end of the week “adventure” in Afghanistan where he and Senators Biden and Hagel were stuck for several hours in the snow on a mountaintop waiting for weather conditions to improve so they could fly on to their destination. Downplaying a potentially very dangerous situation, he joked again that the three Senators were contemplating going outside and using their Senatorial skills to “talk” the Taliban into submission and praised the military personnel who protected them during their “unplanned stopover,” including a helicopter which hovered over them making lots of noise to “rattle the bad guys.”

The Senator clearly loves the grassroots and the netroots — they are part of his blood and his whole approach to political work. He is planning regular blogger calls and I look forward to fruitful discussions with him on the issues facing Massachusetts and the country.

Senator Kerry said he is taking nothing for granted in this Senate race and there is plenty for volunteers and activists to do. The signature drive is in about to go into full swing and there will be lots of events coming up soon. If you live in Massachusetts and you want to get involved, you can contact the John Kerry for Senate campaign office here and they’ll be happy to sign you up. It’s going to be an exciting year for activists. That means Senator Kerry. That means all of us!