Vicki Kennedy is moving and shaking all over town. So, even though she insists she isn't interested in running for the US Senate, her name comes up every time Massachusetts Democrats think about trying to beat Republican Senator Scott Brown in 2012. And they think about it often. To the sorrow of Bay State liberals, Brown remains popular with voters. A Public Policy Polling survey taken in early December gave Brown a 53 percent approval rating. Also, Democrats narrowly favored Ted Kennedy's widow as the best candidate to take him on. Back in August, Kennedy told The Globe's Susan Milligan 'there's only one Senator Kennedy.' As she explained then, 'I think there's more than one way to serve. And for me, that's not it. I have enormous respect for people who do. And I think I can have a wonderful, productive life serving, but that doesn't have to be elective office.' But, ever since, while Kennedy may not be running for office, she's certainly running around Massachusetts. There are Vicki sightings everywhere, including the opening of a North Truro campground, where she was spotted last summer with US Representative William Delahunt. Kennedy played a prominent role in last November's elections, showing up for Democrats such as Governor Deval Patrick, Treasurer-elect Steve Grossman and Auditor-elect Suzanne Bump. Off the campaign trail, she is a constant bold-faced name at a swirl of social events, from a benefit to help epilepsy research at the Museum of Fine Arts to a holiday bash at the Perkins School for the Blind. She was the keynote speaker at the annual Action for Boston Community Development awards dinner, where she impressed organizers by staying until the end of a very long night. She is also part of the vast public relations machine that keeps Camelot alive at the John F. Kennedy Presidential Library and Museum in Dorchester. She participated in commemoration ceremonies marking the 50th anniversary of JFK's historic presidential victory and continues to raise money for the mission she cares most about, the Edward M. Kennedy Institute. The project, which creates another Kennedy compound on the presidential library site, has already received $38.3 million in federal earmark spending. Another $8 million is targeted in the spending bill currently before Congress. Other hints that keep the dream alive: a billboard-sized photo that greeted drivers entering the city from Interstate 93, touting Vicki Kennedy's participation in an event honoring Boston's diversity; and the launching of a Facebook group, 'Vicki Kennedy for Senator of Massachusetts in 2012.' If she does jump in, veteran Democrats predict she would clear the primary field. Kennedy versus Brown promises instant national allure, ensuring a high-profile race and well-financed candidates. Despite Brown's popularity, Democrats want to believe there are openings a strong challenger could use against him - especially in a blue state that totally resisted the red tide that swept over the rest of the country. Brown held up unemployment benefits for tax breaks for the wealthy and is part of the GOP movement to hold up everything until those tax break extensions become law. He reiterated his opposition to the Dream Act, despite months of intense lobbying from advocates and educators that included Harvard University President Drew Faust. The proposal, which would allow some illegal immigrants to qualify for permanent legal residency by graduating from college or trade school, was one of Ted Kennedy's signature causes. Brown's maneuvering around the repeal of 'don't ask, don't tell' also angers traditional Kennedy constituencies. First, Brown said he supported its repeal, then he voted to block efforts to bring repeal to a vote. In 2012, presidential politics could also play a role in Massachusetts. President Obama can count on a Democratic voter surge, although it might be tempered if former Governor Mitt Romney is the Republican nominee. By then, Ted Kennedy may be little more than a distant memory. Or, Massachusetts voters could be missing him and what he championed. Vicki Kennedy's moves now suggest that she's keeping her options open for later. 