(CNN) - Former Sen. Scott Brown of Massachusetts will tout his Granite State roots Thursday as he formally launches a Republican bid for the Senate in neighboring New Hampshire.
And the Republican will criticize the federal health care law and criticize Jeanne Shaheen, the incumbent Democratic senator he hopes to oust in November, saying "I am running to hold Senator Shaheen accountable."
Hours before Brown officially kicks off his campaign, Shaheen's campaign touted its expanding cash war chest.
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Brown, who's entry into the race could turn the contest into one of the most expensive and high profile Senate battles in this year's midterm elections, kicks off his campaign in Portsmouth.
Highlighting his Granite State heritage
The sea coast city's setting emphasizes Brown's roots in the Granite State. His mother lives in the vicinity, he spent a lot of his childhood in the area, and he was born just across the Piscataqua River, in Kittery, Maine.
"Our campaign for the U.S. Senate begins not far from where my life began. I was born right over there at the Naval Shipyard. When my Mom was a young woman, she was a waitress in Hampton Beach, my Dad an airman at Pease. They met, fell in love, and a year or so later I came along. When they carried me home, it was to a house not far from here on Islington Street," Brown will say according to excerpts of his speech released by his his campaign.
Since late year, when he began considering a Senate bid in New Hampshire, Brown's been highlighting his ties to the Granite State, to push back against Democrats' characterizations of him as a "carpetbagger" from Massachusetts.
Obamacare in the spotlight
Brown has made his opposition to the Affordable Care Act, better known as Obamacare, a key part of his campaign, and he'll slam the health care law again as he formally throws his hat into the ring.
"I think of the small business owner I met in Henniker. The guy's paying twice as much for health care now. It's meant some tough decisions he never thought he had to make. And along with our money and our health plans, for a lot of us it feels like we're losing our liberty, too. Obamacare forces us to make a choice, live free or log on – and here in New Hampshire, we choose freedom," Brown will say.
And he'll also attack Shaheen for her support for the law, saying "I worked with Senator Shaheen in the U.S. Senate for three years. She is a nice person, but wrong on the issues facing the people of New Hampshire. She made that clear when she cast the deciding vote that forced Obamacare on this state and our country. A lot of people aren't aware of that vote to pass Obamacare. But it's important to know if we are ever going to get past Obamacare and get America moving in the right direction."
Shaheen's big numbers
As Brown was preparing for his kickoff in Portsmouth, Shaheen reported her best fundraising quarter in her nearly six years in the Senate. Her campaign announced that they raised more than $1.5 million the past three months. They say that brings to $7.3 million the total amount they've raised so far this election cycle, and that they've got $4.35 million cash on hand. The campaign adds that 27,000 people donated to Shaheen in the first quarter, up 12,000 from the previous three months.
"Our campaign is proud of all the grassroots support our campaign has generated to date and we're confident we'll have the resources we'll need to win this November, regardless of whom Republicans nominate to run against Jeanne Shaheen," said her campaign spokesman Harrell Kirstein.
From Massachusetts to New Hampshire
Brown, then a little-known state senator, in Massachusetts, scored an upset victory in a special election in January 2010 to serve the final three years of the term of the late Democratic Sen. Ted Kennedy, who had died the previous summer. Brown lost his bid 2012 re-election bid for a full six-year term to Democratic challenger Elizabeth Warren.
Last year, Brown passed on running in a special election in Massachusetts to fill the term of John Kerry, who left the Senate to become secretary of state. And at the time, Brown also announced that he wouldn't make a 2014 bid for an open governor's seat in the Bay State.
Brown made a number of speaking appearances at GOP events in New Hampshire last year, where he spent much of his childhood and where he owned a vacation home. Last fall, in another hint about a possible run, he dropped the 'MA' from his Twitter handle. A few months later, he sold his home in Massachusetts and moved his residency north to the Granite State.
Last month, Brown announced that he was forming an exploratory committee, which allowed him to raise money and hire staff for a Senate bid. He immediately began a listening tour across New Hampshire. And last Friday CNN confirmed that a former longtime close aide, Colin Reed, had left his job as deputy communications director for New Jersey Gov. Chris Christie to serve as Brown's campaign manager.
Battle over a pledge
Earlier this week Shaheen's campaign once again criticized Brown for not signing a pledge to keep outside money out of the Senate race.
"In 2012, Scott Brown said Massachusetts voters deserved better than outside third-party attack ads. Well, the people of New Hampshire deserve better too. We hope, now that he is officially a candidate, Scott Brown will commit to the same standard he set in his last race on the other side of the border and tell the special interests to stay out," said Mike Vlacich, Shaheen's campaign manager.
Both Brown and Warren signed the pledge in their 2012 contest, but he won't sign the new pledge, saying it comes too late because outside groups have already spent big bucks on the race.
One of those groups, the Ending Spending Action Fund, a pro-Republican outside group, went up this week statewide with a TV commercial that uses a clip of Brown from four years ago slamming the new federal health care law. The spot ends with the narrator saying that "Scott Brown was right on Obamacare then, he's right for New Hampshire Now.
The group put out a spot last year in an effort to convince Brown to run for the Senate in New Hampshire.
Separately, two of the biggest players when it comes to outside spending, Americans for Prosperity (which is backed by the big bucks of the billionaire industrialist Koch Brothers) and American Crossroads (which was co-founded by Karl Rove), have poured more than $1 million into the race, mostly to attack Shaheen for her support of the health care law.
"Scott Brown is for Scott Brown. He moved to New Hampshire and aligned himself with the third party special interest groups trying to buy New Hampshire's Senate seat," said Granite State Democratic Party Chairman Ray Buckley, in a statement.
State of Play
Brown joins three other Republicans who are running for their party's Senate nomination in New Hampshire: former U.S. Sen. Bob Smith, former state Sen. Jim Rubens, and conservative activist Karen Testerman. The winner of the September 9 primary will face off against Shaheen, who moved to New Hampshire 40 years ago and served for six years as the state's governor.
If Brown ends up winning the GOP's September primary, it could expand the map for Republicans. Democrats hold a 55-45 majority in the Senate (53 Democrats and two independents who caucus with the party), but are defending 21 of the 36 seats up in November, with half of those Democratic-held seats in red or purple states, like New Hampshire.
The most recent public opinion polls in a possible Brown-Shaheen November showdown give the incumbent a double digit advantage. According to a Suffolk University/Boston Herald poll conducted in March, Shaheen had a 52%-39% lead among New Hampshire voters. And the senator was up 50%-38% over her potential GOP challenger in an American Research Group survey conducted around the same time.