An Attorney General, A Congressman And A Millionaire Jump Into A Race...

When a Senate seat opens up, it’s natural to think a member of Congress would be the first in line to run for it. Especially in Massachusetts, where it has been 25 years since a seat hasn’t had an incumbent in the running.

Yet all but one of the state’s representatives are saying “no, thank you."

"They looked at the polls," said Jeff Berry, a political science professor at Tufts University. "It wasn’t lack of ambition, certainly."

"I think there’s a lot of people in our congressional delegation who see greatness in the mirror every morning," Berry said, "but the early polling showed that they had name recognition problems; they were way behind Coakley; and they had to think about running a race where they not only got beat, but got beat badly."

The only congressman running is Michael Capuano, who will formally announce later Friday. On the Democratic side, he joins businessman Stephen Pagliuca, who announced Thursday, and Attorney General Martha Coakley.

Berry said Coakley has a head start on Capuano.

"I think Capuano has to be very disappointed that labor is not rallying around him, because he believes he’s the most liberal person in the race and that he’s been in Congress carrying labor’s water," Berry said, "whereas Attorney General Coakley really has not been in a position to do much for labor."

But Martha Coakley has 10 endorsements from labor organizations, including the Teamsters. In a race that has only 11 weeks until the primary, political watchers say the early momentum and the money are going to Coakley.

Each candidate must gather 10,000 signatures to get on the ballot. Coakley is already halfway there, with a large cadre of volunteers. It puts her in a strong position, said Washington-based political analyst Stuart Rothenberg.

"Well, Coakley was obviously out of the gate first," Rothenberg said. "She’s clearly committed to this, she’s raising money and, as other candidates drop to the sidelines, it would seem to enhance her positioning as a known commodity, an elected official and, of course, a woman in the race."

It’s difficult to get a complete picture of each candidate’s financing because the Federal Election Commission doesn’t require disclosures until October.

Capuano starts off with $1.2 million in his campaign account from previous elections. Stephen Pagliuca's personal wealth is estimated at around $400 million. And Coakley, who started with no previous campaign funds, now has the endorsement of the influential Emily’s List. It's featuring her on its homepage and encouraging 100,000 members to support her campaign.

Boston College political science professor Dennis Hale said money will be very important in the short race.

"There is now a candidate, Stephen Pagliuca, who has enough money to finance his own campaign," Hale said. "Martha Coakley, meanwhile, has the opportunity to raise money in the national political networks — women's political networks — outside the state. I don’t think Capuano has that same kind of ability to raise money outside of Massachusetts. I mean, who is he? He’s just a guy who represents a district in Massachusetts."

Capuano, in his sixth term, is trying to raise his visibility in the state with his first TV commercial of the campaign.

"Only one candidate stood with Ted Kennedy against Bush’s Iraq war and mirrors his progressive record," the commercial starts. "Mike Capuano."

Political watchers say the candidates will spend a lot of money on television. Pagliuca has an ad ready to go starting Friday. He knows the race will not be easy.

"Sometimes people make public service a blood sport, and I don’t think it should be a blood sport," Pagliuca said. "Martha Coakley has done a good job for this state and so has Rep. Capuano. They have experience in politics — I have experience in business."

Pagliuca, a Celtics co-owner and Bain Capital executive, says he’ll spend an appropriate amount of money to run against seasoned politicians with name recognition. That could go a long way, said political scientist Hale.

"Money buys visibility, it buys organization, it buys credibility," Hale said. "I mean, after all, it was money that got Ted Kennedy visibility and name recognition in 1962. He was basically just somebody’s brother."

And right now, Martha Coakley is just the attorney general, Michael Capuano is just a congressman, and Stephen Pagliuca is just a millionaire businessman. All with the desire to fill the shoes of Ted Kennedy, who was once just somebody's brother.

WBUR's coverage of the Sprint To The Senate continues next week with profiles of the Republican candidates.