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The Kennedy family's return to power rests on the shoulders of a 31-year-old lawyer and former Peace Corps volunteer who has never campaigned for public office.

Joseph Kennedy III announced Thursday that he is running for Congress, in the Massachusetts district currently represented by retiring Democratic Rep. Barney Frank. In doing so, the grandson of the late Robert F. Kennedy is vying to carry the family mantle back to Washington after the death of Sen. Ted Kennedy in 2009 left a void. When former Rep. Patrick Kennedy departed Congress in early 2011, the Democratic dynasty for the first time in decades was gone from the capital.

But for Joseph, the luster of the family name is quickly proving to be, simultaneously, his biggest asset and most imposing hurdle.

Sean Bielat, a Republican who unsuccessfully ran against Frank in 2010, has tried to portray Kennedy's candidacy as one of privilege as he vies again for the 4th District seat.

Bielat has skewered the young Kennedy as unqualified and seeking to cash in on "political entitlement." In a local interview, the GOP candidate questioned whether the "romanticism" is still attached to his family name and suggested the race would "shift" away from the Kennedy "myth" and become more about the candidate himself.

On the day Kennedy announced, Bielat's campaign tweeted: "Please (retweet) if you believe the LAST thing this nation needs is another 'Kennedy Seat.'"

It's an argument that worked well for Sen. Scott Brown when he ran for the seat held by Ted Kennedy. A breakout moment for the fish-out-of-water, truck-driving Massachusetts Republican came when he chastised a debate moderator for using the term, "Teddy Kennedy's seat."

"It's the people's seat," Brown said.

Voters went on to reject the Democrats' chosen candidate, Martha Coakley.

But Joseph Kennedy, whose father Joseph P. Kennedy II was a U.S. congressman, nevertheless can tap into a ready and eager network of support to mount what will undoubtedly be a formidable campaign

Kennedy entered the race with big-time union support, including from the SEIU. The family connections already have helped him build a fundraising infrastructure -- and he'll reportedly be in Washington next week to pump up the campaign coffers.

The Massachusetts GOP, in the face of the young Kennedy's fundraising prowess, said in a statement that "the age of coronations is over in Massachusetts."

But Frank, in an interview on MSNBC Friday, denied that entitlement was behind the Kennedy run.

"There isn't a trace in him of any sense that this is by right or by inheritance. This is not a guy who thinks he's entitled to anything," Frank said. He added that Kennedy is a "better campaigner than I was."

In his campaign launch video, the earnest-looking and soft-spoken Kennedy framed his pitch -- much like President Obama -- around the idea of "fairness," in the tax code, housing policy, jobs policy and everywhere else.

"I believe this country was founded on a simple idea -- that every person deserves to be treated fairly by each other and by their government. But that's not happening in America anymore," Kennedy said.

Urging voters to join him in his "fight for fairness," Kennedy briefly invoked his family history, and vowed humility: "My family has had the great privilege of serving Massachusetts before. They taught me that public service is an honor given in trust, and that trust must be earned each and every day. That's exactly what I intend to do."

A few other Democrats are running for the 4th District seat. Bielat is competing on the GOP side against former state mental health commissioner Elizabeth Childs.

It's not a clear path to Congress, but Kennedy may still represent the family's best shot at a return to public office. Kennedy most recently was a prosecutor for Middlesex County in Massachusetts. He graduated from Harvard Law School, and before that Stanford.

On the John F. Kennedy tree, daughter Caroline briefly attempted a run at the New York Senate seat previously held by Hillary Clinton when she was tapped for secretary of state. A lackluster campaigner, Kennedy later withdrew from the race. She remains president of the John F. Kennedy Library Foundation.

The other members of the Kennedy family are almost all in private life.

Robert F. Kennedy Jr. is a professor and environmental attorney.

Kathleen Kennedy Townsend, the former Maryland lieutenant governor who mounted an unsuccessful run for governor, serves on various boards including that of the Kennedy Library Foundation. Both Robert and Kathleen are children of Robert F. Kennedy.

Joseph Kennedy III's father continues to run a nonprofit he founded in 1979 that specializes in providing cheap heating oil to those in need.

The late Sen. Ted Kennedy's son Edward Jr. runs a financial services firm in New York City.

One other member of the family is in public office, though. Robert Sargent Shriver III serves on the Santa Monica City Council. Shriver is the son of John F. Kennedy's sister Eunice.